Statement of Principles concerning accidental hypothermia (Reasonable Hypothesis) (No. 23 of 2026)

Definitions and scope are central to this instrument. The medical condition covered is narrowly characterised. “Accidental hypothermia” is not a lay description; it is defined in clinical terms as the unintentional lowering of core body temperature to 35 degrees Celsius or lower due to exposure to low environmental temperature, and it requires the absence of a primary disturbance of thermoregulation (section 7(2)(a)). The instrument explicitly excludes intentionally induced hypothermia and hypothermia arising from toxicologic or pharmacologic causes (section 7(2)(b)). Although the ICD-10-AM code T68 is acknowledged in the instrument, the operative definition for claims is the textual definition in section 7(2) rather than solely an ICD-10-AM code (section 7(3)).

A second key concept is the treatment of death. Death “from accidental hypothermia” is defined to include death from any terminal event or condition that was contributed to by the person’s accidental hypothermia (section 7(4)). The Schedule defines “terminal event” by listing examples such as pneumonia, respiratory failure, cardiac arrest, circulatory failure, or cessation of brain function (Schedule 1). That means in claims where a listed terminal event is alleged as the proximate or ultimate cause of death, the claimant may rely on the Statement of Principles if accidental hypothermia contributed to that terminal event (section 7(4); Schedule 1).

Causation is cast in statutory terms. The Authority sets out minimum factors that must exist to raise a reasonable hypothesis linking the condition to relevant service. At least one of the factors in section 9 must be present: exposure to low environmental temperature at the time of clinical onset, or inability to obtain appropriate clinical management for accidental hypothermia before clinical worsening (section 9). The instrument provides a non‑exhaustive note identifying contexts in which exposure might occur, including military training and exercises, occupational exposure (for example cold room), psychiatric disease or suicide attempt, substances or diseases affecting consciousness, injury or disease affecting mobility, diseases impairing cognition, and homelessness (section 9 note). These are illustrative and not prescriptive.

The relationship to service is governed by section 10. Any factor from section 9 that is relied on must be related to the person’s relevant service, and the instrument clarifies that the “clinical worsening” element of the factors in section 9 applies only to material contribution to, or aggravation of, accidental hypothermia where the hypothermia was suffered or contracted before or during but did not arise out of the person’s relevant service (section 10(1)-(2)). The Schedule defines “relevant service” by reference to categories under the VEA and MRCA, including operational, peacekeeping, hazardous, British nuclear test defence service, warlike, and non‑warlike service (Schedule 1).

Finally, the instrument sets its authority and limits. It is an instrument made under subsection 196B(2) of the VEA (section 3) and is expressly a Statement of Principles issued for the statutory claims system; it does not itself create entitlements or procedure, but it is an evidentiary/medical standard used in claims covered by the VEA and MRCA (section 5, section 3).

The instrument’s primary legal subjects are persons making or affected by claims to which section 120A of the VEA or section 338 of the MRCA applies (section 5). Those categories, as defined in Schedule 1, encompass veterans and members of the Forces who rendered “relevant service”, specifically operational, peacekeeping, hazardous, British nuclear test defence service under the VEA, and warlike and non‑warlike service under the MRCA (Schedule 1). The instrument therefore affects claimants who served in the specified categories and their dependants where death from accidental hypothermia is alleged to have contributed to a terminal event.

Secondary stakeholders include the Repatriation Medical Authority, which made the Statement under statutory authority (section 3), and the administrative bodies responsible for determining claims under the VEA and MRCA. Although the instrument does not name a particular decision maker for claims, it is issued for the claims processes specified in section 5 and will be applied by the decision makers under those Acts when assessing whether a reasonable hypothesis has been raised. The instrument itself does not specify adjudicative procedures; it supplies the medical‑causation criteria that feed into those processes (section 5).

Medical practitioners and medical experts who provide evidence in support of or against claims will be affected in practice because the instrument defines the clinical parameters of the condition and the causation factors that are indicative of a reasonable hypothesis (section 7(2); section 9). For example, a clinician instructed to assess whether a veteran’s death involved accidental hypothermia will work against the textual definition of accidental hypothermia in section 7(2) and assess whether the factors in section 9 are present and related to relevant service (section 10).

Other parties that may be indirectly affected are employers or insurers in cases where the factual circumstances of exposure implicate occupational settings. The instrument’s note under section 9 expressly recognises occupational exposure (for example cold room) as a circumstance in which exposure to low environmental temperature may occur. That means incidents occurring in civilian workplaces can fall within the factual examples envisaged by the Statement, albeit only in the context of a claimant who has relevant service and brings a statutory claim under the VEA or MRCA (section 9 note; section 5). The instrument does not, however, create or modify workplace safety law or private insurance entitlements beyond its role within veterans’ compensation law.

Finally, the instrument affects administrative record‑keeping and evidentiary practices for agencies handling VEA and MRCA claims, because decision makers will need to consider whether claim files show the required factors and their relationship to service per sections 9 and 10 and the Schedule definitions.

This instrument is a Statement of Principles; it does not itself impose criminal offences, civil liabilities, or regulatory duties outside the operation of the VEA and MRCA claims frameworks. Its legal effect is to set out the medical condition and the factors that the Repatriation Medical Authority regards as sufficient to raise a reasonable hypothesis linking accidental hypothermia or death from it to relevant service (section 8; section 9). Consequently, the primary “duties” and “rights” it creates are procedural and evidentiary within claims processes under the VEA and MRCA.

Rights of claimants. Claimants have the right to have their claim assessed against these principles when the claim falls under the specified provisions of the VEA or MRCA (section 5). That means a claimant alleging accidental hypothermia, or death contributed to by accidental hypothermia, can rely on the definitions and factors contained in this instrument when arguing that a reasonable hypothesis exists connecting the injury or death to relevant service (section 7; section 9). The instrument’s inclusion of death from accidental hypothermia (section 7(4)) means dependants or estate representatives have a pathway to invoke these principles where appropriate.

Duties of decision makers. Adjudicators and administrative decision makers charged with determining claims governed by the VEA and MRCA are expected to apply this Statement as the medical‑causation standard for accidental hypothermia claims. The instrument itself does not specify administrative procedures or timelines. It does require, however, that decision makers assess whether at least one of the factors in section 9 exists and whether that factor is related to relevant service as defined in Schedule 1 and further qualified in section 10(1)-(2). The Authority’s statement that there is “sound medical‑scientific evidence” underpinning the link (section 8) signals the instrument’s role as an evidentiary standard in claims assessment rather than as a substitute for clinical judgment.

Interplay with other Statements of Principles. Where a factor in section 9 refers to an injury or disease covered by another Statement of Principles, that other Statement applies in accordance with its terms (section 11). That places a duty on decision makers to consult other Statements where cross‑referenced conditions appear on the face of the factors; rights and duties then follow from the terms of those other Statements.

No penalties or enforcement powers in this instrument. The instrument does not create any penal sanctions, regulatory fines, or enforcement mechanisms; it is confined to defining clinical and causation matters for the statutory claims process (sections 3, 5). Any obligation to provide evidence, attend examinations, or the like would derive from the VEA or MRCA procedural provisions, which are outside the text of this instrument. The instrument does not purport to alter entitlements or the standard of proof for decision makers; it specifies what will raise a reasonable hypothesis for the particular condition (section 9).

Limitations and exclusions. The instrument establishes exclusions that are essential to how rights will be treated. Hypothermia intentionally induced, or arising from toxicologic or pharmacologic causes, is excluded from the definition of accidental hypothermia for the instrument’s purposes (section 7(2)(b)). That exclusion operates as a threshold limit on the rights that a claimant may exercise under this Statement.

The Statement of Principles contains no penalty provisions and no direct enforcement mechanisms. It is a medical‑causation instrument made under subsection 196B(2) of the Veterans' Entitlements Act 1986 and is designed to be applied in statutory claims under the VEA and MRCA (section 3; section 5). The instrument itself does not create offences, fines, sanctions, or regulatory compliance regimes. There are therefore no monetary penalties or criminal sanctions stated within this instrument for non‑compliance or misstatement with respect to its content.

Enforcement in practice. Enforcement implications arise indirectly through the claims processes under the VEA and MRCA. Because the instrument specifies the factors that will raise a reasonable hypothesis linking accidental hypothermia to relevant service (section 9), decision makers in those statutory schemes will use the Statement as a medical standard when deciding entitlement. Any consequences for claim outcomes, including acceptance or rejection of liability for compensation, result from the application of the Statement within those frameworks, not from the Statement itself (see section 5).

Administrative decision‑making and potential review avenues. The instrument does not set out administrative review or appeal routes. Those are functions of the VEA and MRCA administrative and review regimes, which determine procedural remedies and consequences of an adverse decision. The Statement may therefore affect the content of medical evidence considered on review and appeal but it does not prescribe the review procedure or remedies.

No investigatory powers. The Statement does not confer investigatory powers on the Repatriation Medical Authority or on claims administrators. The Authority’s role is to determine the Statement of Principles (section 3) and to record its view that “sound medical‑scientific evidence” supports the connection between accidental hypothermia and relevant service (section 8). Any statutory investigative or enforcement powers remain those conferred elsewhere in the VEA or MRCA and are not created or modified by this instrument.

Interaction with other legal accountability regimes. The instrument’s content may be used by administrative decision makers in compensatory contexts. It does not, however, displace obligations in other legal domains such as workplace health and safety, coronial inquests, criminal investigations, or civil tort claims. The Statement does not purport to limit or expand the operation of those regimes; it simply defines what the Repatriation Medical Authority regards as raising a reasonable hypothesis for the specific statutory purpose set out in section 5.

Direct statutory connections are articulated within this instrument. The Statement is made under subsection 196B(2) of the VEA (section 3), and it applies specifically to claims covered by section 120A of the VEA or section 338 of the MRCA (section 5). The instrument therefore functions within the legal architecture of those Acts as the Repatriation Medical Authority’s Statement of Principles for accidental hypothermia, and must be read as part of the body of Statements the Authority issues under subsection 196B(2). The Schedule defines key statutory terms, including VEA and MRCA and the categories that constitute “relevant service” (Schedule 1).

ICD classification. The instrument acknowledges the ICD‑10‑AM coding system by reference to code T68 for accidental hypothermia but clarifies that the operative meaning of accidental hypothermia for the purposes of the Statement is the textual definition in section 7(2). A reference to ICD‑10‑AM code is made specific to the Tenth Edition, effective date 1 July 2017 (section 7(3)). That ties the clinical description to an internationally recognised diagnostic classification while preserving the primacy of the instrument’s definition.

Cross‑application with other Statements of Principles. The instrument explicitly provides for cross‑application where a factor in section 9 refers to an injury or disease covered by another Statement: that other Statement applies according to its terms (section 11). This creates an interactional rule that prevents internal inconsistency between Statements of Principles: where overlap occurs, the additional Statement governs the referenced injury or disease.

No substitution of other laws. The instrument does not repeal or alter other substantive laws outside its remit. It repeals only the previous Statement of Principles on the same subject (section 4). Any modifications to entitlements, procedural rules, or substantive legal obligations under the VEA, MRCA, or other statutes must be made under those statutes and are not effected by this Statement.

Evidence and procedural law left to VEA and MRCA. The Statement provides the medical criteria and causation factors for accidental hypothermia claims, but it does not prescribe evidentiary standards, burdens of proof, procedural timelines, or administrative remedies. Those procedural and evidentiary matters remain governed by the VEA and MRCA and their implementing regulations and policies. Consequently, practitioners must apply this Statement alongside the procedural rules in the relevant Act rather than treating it as a standalone procedural instrument (section 5; section 3).

Interaction with clinical practice and external classification systems. The Statement will influence how clinicians and medical experts frame reports for the statutory claims system because it specifies the clinical threshold (core body temperature 35 degrees Celsius or lower) and exclusions (primary disturbance of thermoregulation; intentional induction; toxicologic or pharmacologic causes) (section 7(2)). The instrument’s reference to ICD‑10‑AM situates the Statement within recognised clinical coding practices, but the textual definition is controlling for claims purposes (section 7(3)).

This instrument expressly repeals the prior Statement of Principles concerning accidental hypothermia (No. 21 of 2018) (Federal Register of Legislation No. F2018L00200) that was made under subsection 196B(2) of the VEA (section 4). The current instrument is numbered No. 23 of 2026 and is dated 20 February 2026, and it commences on 23 March 2026 (front matter; section 2). The instrument states that it was determined by the Repatriation Medical Authority and signed on behalf of the Authority by its Chairperson (front matter). The instrument identifies its authority as subsection 196B(2) of the VEA (section 3).

No further amendments, transitional provisions, or savings clauses are included in this text. The instrument does not refer to any modifications of the VEA or MRCA themselves, nor does it provide that rights or liabilities under the repealed 2018 Statement continue to be assessed under that prior Statement for claims made before commencement. Practitioners should therefore assume that from the commencement date the new Statement is the operative Statement of Principles for accidental hypothermia claims governed by the cited sections of the VEA and MRCA, unless separate legislative or administrative guidance provides transitional arrangements.

Because the instrument is framed as a Statement of Principles made under a statutory provision that contemplates periodic review and issue of Statements by the Repatriation Medical Authority, future amendments would be effected by subsequent Statements or instruments made under the same statutory provision. This instrument does not set out any sunset clause or schedule for review. The Schedule to this instrument contains the dictionary definitions current as at commencement; any future amendments to definitions, cross‑references, or lists of relevant service categories would require a further instrument.

Practitioners should note that the instrument explicitly references the ICD‑10‑AM, Tenth Edition, effective date 1 July 2017, for the purposes of identifying the code assigned to accidental hypothermia (section 7(3)). If that external classification is updated in future, the instrument does not itself adopt later editions; any change in the ICD reference in the Statement would require amendment of the Statement.

The instrument does not record any case law, judicial consideration, or litigation history. It is a Statement of Principles determined by the Repatriation Medical Authority under subsection 196B(2) of the VEA (section 3). There is no material within the instrument that purports to summarise or list decisions, appeals, or judicial determinations that have applied this particular Statement of Principles or its predecessor. The instrument does not cite any cases, and the Schedule does not include any judicial interpretations or references.

Because the text contains no litigation history, practitioners seeking authoritative guidance on how courts or tribunals have treated the factors in this Statement will need to consult external case law databases and decision records of the relevant administrative review bodies. Any judicial or administrative decisions that interpret the scope, meaning, or application of terms such as “reasonable hypothesis”, “clinical onset”, “material contribution”, or “inability to obtain appropriate clinical management” will be found in the decisions under the VEA and MRCA regimes, not in this instrument. The instrument itself states the Repatriation Medical Authority’s view that there is sound medical‑scientific evidence for the link between accidental hypothermia and relevant service (section 8), but it does not record or summarise judicial responses to that view.

In practice, litigation history relevant to this instrument will develop in the context of claims litigation under the VEA and MRCA, where administrative decisions applying this Statement are challenged on questions such as whether a reasonable hypothesis was raised, whether the factors are present and related to relevant service, and whether cross‑referenced Statements have been properly applied (section 11). The present instrument contains no record of such litigation.

Several points in the instrument can lead to misunderstandings or procedural pitfalls if they are not attended to carefully.

Definition controls over ICD code. While the instrument notes that accidental hypothermia attracts ICD‑10‑AM code T68 (section 7(3)), it also expressly states that for the purposes of this Statement the meaning is the textual definition in section 7(2). Relying solely on an ICD code without showing the textual elements , unintentional lowering of core body temperature to 35 degrees Celsius or lower due to exposure to low environmental temperature, and absence of a primary disturbance of thermoregulation , will not satisfy the Statement’s definitional requirement (section 7(2), section 7(3)).

Exclusions are explicit and narrow the scope. The instrument excludes intentionally induced hypothermia and hypothermia due to toxicologic or pharmacologic causes (section 7(2)(b)). If evidence shows that hypothermia followed medical induction, therapeutic cooling, overdose of sedative or other pharmacologic agents, or toxicologic exposure, the condition is outside the instrument’s coverage. Practitioners must look for evidence of intentional induction or substance‑related causation and address those issues in claim documentation.

“Primary disturbance of thermoregulation”. The definition of accidental hypothermia requires that the individual lacks a primary disturbance of thermoregulation (section 7(2)(a)). The instrument does not define “primary disturbance of thermoregulation” further. That creates an evidential issue where a claimant has pre‑existing conditions affecting thermoregulation. Absent further guidance in the instrument, claimants and decision makers must locate medical evidence addressing whether thermoregulatory dysfunction was primary and therefore excluded.

Clinical timing matters. The instrument requires “exposure to low environmental temperature at the time of the clinical onset of accidental hypothermia” as one of the factors that will raise a reasonable hypothesis (section 9(1)). Establishing the timing of exposure relative to clinical onset will therefore be critical. Where the sequence of events is unclear , for example where an incapacitating event occurred and the individual was later exposed , the claimant must link exposure to the clinical onset in a way consistent with section 9.

“Clinical worsening” element is limited. The second factor in section 9 concerns “inability to obtain appropriate clinical management for accidental hypothermia before clinical worsening” (section 9(2)). Section 10(2) restricts the clinical worsening aspect to cases where the person’s accidental hypothermia was suffered or contracted before or during, but did not arise out of, the person’s relevant service. This is a nuanced limitation: clinical worsening can only be relied on as a factor to the extent that it materially contributed to or aggravated accidental hypothermia in the specified temporal and causal circumstances (section 10(2)). Misapplying the clinical worsening factor to cases where hypothermia arose out of service or where the temporal sequence is different could lead to incorrect conclusions.

Cross‑referencing with other Statements. Section 11 provides that if a factor in section 9 refers to an injury or disease covered by another Statement, that other Statement applies according to its terms. Practitioners must identify when factors invoke other Statements and then apply those Statements’ terms. Failing to do so can produce inconsistent argumentation or incomplete reliance on authoritative medical criteria.

Terminology not exhaustively defined. Several operational terms used in the instrument are not exhaustively defined. Examples include “exposure to low environmental temperature”, “clinical onset”, “appropriate clinical management”, and “material contribution”. The instrument’s note under section 9 gives examples of contexts for exposure, but those examples are illustrative rather than exhaustive. These open terms create potential for contest on the facts in claims and for variation in expert evidence.

No procedural or evidentiary detail. The Statement does not set out the form of evidence required to establish the factors, nor does it specify evidentiary thresholds or procedural steps in the claims process (sections 3 and 5). Practitioners cannot rely on the Statement alone to guide evidentiary strategy; they must pair it with the procedural rules and evidentiary expectations of the VEA and MRCA decision makers.

Applicability limited to specified claims. The instrument applies only to claims under section 120A of the VEA or section 338 of the MRCA (section 5). It is not a general medical standard for clinical practice, nor does it create entitlements outside those statutory contexts. Users of the Statement should not attempt to extend its coverage beyond the expressly stated claims framework.

Relevance of “relevant service” categories. The Schedule’s definition of “relevant service” is categorical and must be checked in every claim (Schedule 1). Misclassifying a person’s service category could incorrectly prevent application of the Statement in a claim where it should apply, or incorrectly import the Statement where it should not.

This instrument is not a compliance checklist in the regulatory sense; it is a medical‑causation Statement of Principles to be used in statutory claims under the Veterans’ Entitlements Act 1986 and the Military Rehabilitation and Compensation Act 2004 (section 5; section 3). Compliance, therefore, means ensuring that claims and supporting evidence are aligned with the definitions and causation factors set out in the Statement.

Establish the operative definition. A claimant should ensure that the medical evidence addresses the textual definition of accidental hypothermia in section 7(2): unintentional lowering of core body temperature to 35 degrees Celsius or lower due to exposure to low environmental temperature, in an individual without a primary disturbance of thermoregulation. The Statement emphasises the core temperature threshold and the exposure‑based causal mechanism as defining features (section 7(2)(a)).

Address exclusions. Medical evidence must directly address exclusions in section 7(2)(b). If there is any suggestion of intentionally induced hypothermia, or of toxicologic or pharmacologic causation, the claimant should ensure that the evidence rules those out for the purposes of the Statement, because such causes are explicitly excluded.

Identify and prove at least one factor in section 9. To raise a reasonable hypothesis a claimant must show at least one of the factors listed in section 9:

• Exposure to low environmental temperature at the time of clinical onset of accidental hypothermia (section 9(1)). Evidence should, at minimum, allow a decision maker to conclude that exposure occurred at the relevant time.

• Inability to obtain appropriate clinical management for accidental hypothermia before clinical worsening (section 9(2)). Where this factor is relied on, claimants should pay careful attention to the temporal and causal limitation in section 10(2), which confines the clinical worsening element to cases where hypothermia was suffered or contracted before or during, but did not arise out of, relevant service.

Relate the factor to relevant service. Section 10(1) requires that any factor in section 9 relied on must be related to the person’s relevant service as defined in Schedule 1. Practically, that means claimants should obtain and present service records, duty statements, training itineraries, unit logs, or similar documentation where appropriate to show how the exposure or lack of clinical management connects to the person’s service category (Schedule 1; section 5). The Statement itself does not prescribe which documents satisfy this requirement; those procedural aspects are governed by the VEA and MRCA claims systems.

Check cross‑references to other Statements. If any factor invoked refers to another injury or disease that has its own Statement of Principles, ensure that the other Statement is identified and complied with, because section 11 requires application of the other Statement according to its terms. Practitioners should collect and analyse evidence in line with both Statements where overlap exists.

Address “primary disturbance of thermoregulation”. Given the need to show the absence of a primary disturbance of thermoregulation for the definition to apply (section 7(2)(a)), claimants whose medical histories include conditions affecting thermoregulation should commission or obtain medical reports that directly assess whether a primary thermoregulatory disturbance existed and whether it was causal.

Document timing and sequence. Because the factors depend on timing , for example, “at the time of the clinical onset” and “before clinical worsening” , contemporaneous or retrospective clinical records that establish when symptoms began, when exposure occurred, and when medical management was or was not obtained will be important. The Statement does not specify evidentiary form; VEA and MRCA procedural rules control admissibility and weight.

Use the ICD‑10‑AM reference appropriately. While the instrument references ICD‑10‑AM code T68 (section 7(3)), the operative definition is the textual one in section 7(2). Medical codings can be used as supportive data, but reports should explicitly address the instrument’s definitional elements.

Recognise that the Statement does not set procedural steps. The instrument does not tell claimants where to file evidence, what medical examinations are required, or how to lodge a claim. Those procedural matters follow the VEA and MRCA statutory and administrative frameworks. Practitioners should combine the medical elements required by this Statement with the procedural checklists and timelines dictated by the relevant Act and by administering agencies (section 5).

Prepare for factual contestation. Several terms in the instrument are open to factual contest , for example, “exposure to low environmental temperature”, “appropriate clinical management”, and “material contribution”. Prepare medico‑legal reports that address these concepts directly, and anticipate that decision makers may require detailed factual submissions tying service records to exposure or to failures of clinical management.

Confirm applicability to the specific claim. Before investing in evidence, check that the person’s service falls within the “relevant service” categories in the Schedule (Schedule 1). If the person’s service does not fit those categories, this Statement will not apply even if the factual circumstances otherwise match.

Record reliance on the Statement itself. Where claims are made under the VEA or MRCA and accidental hypothermia or death from accidental hypothermia is alleged, expressly identify and rely on this Statement of Principles in submissions to the decision maker so the medical‑causation standard is applied. Include references to the specific provisions relied upon (for example section 7(2), section 9, section 10) to focus the adjudicator’s attention on the relevant criteria set by the Authority.