Hypothermia and Cold Injury First Aid: What Changed in ANZCOR Guideline 9.3.3
ANZCOR Guideline 9.3.3 covers generalised hypothermia and local cold injury in adults, children and infants. The 2026 update specifically notes the problem of rapid rewarming in non-freezing cold injuries. That addition is important because not every cold-exposed limb is frostbitten, and different cold injuries should not be treated as though they are identical.
Hypothermia, frostbite and non-freezing cold injury are different
Hypothermia is a fall in core body temperature below 35 degrees Celsius. Frostbite is a freezing injury in which tissue freezes. Non-freezing cold injury, including trench foot or immersion foot, results from prolonged exposure to cold and wet conditions above freezing. The tissue may be pale, numb, weak or immobile even though ice crystals have not formed.
Recognising the difference matters because first aiders should not automatically apply an aggressive frostbite rewarming method to every cold, numb extremity. The full guideline should be followed, and urgent medical advice is appropriate when there is significant pain, altered sensation, colour change, blistering, impaired movement or uncertainty about the type of injury.
Core first aid principles remain
- Move the person to shelter and reduce further heat loss.
- Call for help when hypothermia or significant cold injury is suspected.
- Follow DRSABCD and begin CPR for a person who is unresponsive and not breathing normally.
- Use insulation and a vapour barrier, such as blankets combined with plastic wrap, to reduce ongoing heat loss.
- Use safe active rewarming for hypothermia, with heat applied to the torso and protection between the heat source and the skin.
- Remove jewellery from an affected limb where possible and elevate it.
- Do not rub injured tissue, use direct radiant heat or break blisters.
- Avoid walking on affected feet and prevent refreezing.
What the rapid-rewarming update means for training
The update highlights a common first aid risk: using one simple instruction for all cold injuries. First aid education should teach learners to identify whether the problem is whole-body cooling, frozen tissue or prolonged non-freezing exposure. When the diagnosis is uncertain, the safest approach is gentle protection, prevention of further cooling, avoidance of rubbing or direct heat, and prompt professional assessment.
Specialist wilderness or alpine rescue teams may use more detailed rewarming methods for deeply frozen tissue, but these techniques require training, pain control, temperature control and a clear plan to prevent refreezing.
The practical takeaway
Cold injury first aid is not simply about making the person hot as quickly as possible. Protect the person from further exposure, manage life threats first, distinguish hypothermia from local cold injury, avoid damaging heat or friction, and use the current ANZCOR guidance for the specific presentation.
Continue your training
Environmental emergencies are easier to manage when first aiders have practised assessment and safe rewarming decisions. Include cold-exposure scenarios in workplace and outdoor first aid training.
Primary clinical source: ANZCOR Guideline 9.3.3 – First Aid Management of Hypothermia and Cold-Related Injuries
Publication disclaimer: Educational summary only. It does not replace the full ANZCOR guideline, local policy, formal training or clinical judgement. Verify the current official guideline before publication or clinical use.
