Shivering, slurred speech and an unsteady gait can mean hypothermia: replace wet clothing, wrap up and warm the torso first
Hypothermia means core temperature below 35°C, with shivering, slurred speech, imbalance and confusion. Remove wet clothes, wrap in dry clothing or a blanket, and warm the torso before the hands and feet. The source recommends hot sweet drinks and no alcohol, which suppresses shivering. Stopping shivering can indicate deterioration, not recovery. If the person is unresponsive and not breathing normally, begin CPR; unconsciousness alone is not an indication.
What it takes
A foil emergency blanket costs a few RMB in China; carry dry spare clothing. Learning the signs is free.
What you may gain
US National Weather Service guidance defines hypothermia below 95°F (35°C), advises immediate care for cold, slowed or confused people, moving indoors and rewarming the body's center first, and warm drinks. Alcohol reduces shivering and should be avoided. The cited weather page says to perform CPR for unconsciousness, but that abbreviated wording is corrected here: current first-aid guidance requires unresponsiveness and absent or abnormal breathing. Frostbite should be rewarmed with warm water or body heat, not hot water or radiant heat such as a fireplace. The Wilderness Medical Society's 2019 document is a clinical guideline for this setting.
Context & considerations
Do not rub limbs, use a hot bath or handle the person roughly: severe hypothermia makes the heart vulnerable to arrest. Loss of shivering is not reassuring. Only the Wilderness Medical Society abstract was verified because the full text required subscription. Safety correction: the original instruction based on unconsciousness alone has been replaced with the breathing-and-response criteria in current St John Ambulance CPR guidance.
Research & references
US National Weather Service. During Extreme Cold. https://www.weather.gov/safety/cold-during; Dow J et al. (2019). Wilderness Medical Society Clinical Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2019 Update. Wilderness & Environmental Medicine. https://doi.org/10.1016/j.wem.2019.10.002; St John Ambulance. How to do CPR on an adult. https://www.sja.org.uk/first-aid-advice/cpr/