Hypothermia: Recognizing the Signs and Saving a Life

Hypothermia kills silently every winter. Contrary to popular belief, it doesn't only affect mountaineers or the homeless: poorly equipped hikers, motorists whose cars have broken down, elderly people at home, wet children... This life-threatening emergency can strike anyone, anywhere. Overcoming this situation often depends on the ability of those around the person to recognize the early signs and act quickly with the right actions.

Understanding hypothermia

Definition and critical thresholds

Hypothermia is defined as a core body temperature below 35°C . This drop triggers a cascade of potentially fatal physiological dysfunctions. The human body functions within a very narrow temperature range: 36.5-37.5°C.

Severity thresholds :

• Mild hypothermia : 32-35°C (consciousness preserved)
• Moderate hypothermia : 28-32°C (altered consciousness)
• Severe hypothermia : <28°C (loss of consciousness, cardiac arrest)

Above 32°C, the prognosis remains favorable with appropriate warming. Below that, each degree lost exponentially increases the risk of death.

Unknown risk factors

Age is the main factor: the elderly (with impaired thermoregulation) and children (who cool down rapidly) are more susceptible. Aggravating medical conditions make certain individuals more vulnerable to hypothermia: diabetes, hypothyroidism, malnutrition, and alcoholism can transform moderate exposure to cold into a more serious situation.

Physical exhaustion dramatically accelerates hypothermia. A tired bushcrafter or hiker can therefore develop hypothermia in a matter of minutes if conditions deteriorate.

Recognizing vital signs

Phase 1: Mild hypothermia (35-32°C)

Intense shivering : the body attempts to produce heat through muscle contractions. These exhausting shivers consume a great deal of energy and paradoxically accelerate cooling.

Behavioral changes : irritability, mild confusion, clumsiness. The person stumbles, has difficulty manipulating simple objects. Physical signs : pale and cold skin, numb extremities, slowed speech.

Phase 2: Moderate hypothermia (32-28°C)

The shivers stop abruptly : an alarming sign indicating the depletion of energy reserves. This absence marks entry into the danger zone.

Severe mental impairment : significant confusion, drowsiness, incoherent speech. The victim may make delusional statements, undress due to a paradoxical sensation of heat.

Cardiovascular signs : slow and weak pulse, low blood pressure, irregular heartbeat.

Phase 3: Severe hypothermia (<28°C)

Loss of consciousness : coma, shallow and irregular breathing. Muscle rigidity giving the impression of death. Apparent cardiac arrest : imperceptible pulse.

Vital rule : never declare a hypothermic person dead until they have been warmed up. "No one is dead until they are warm and dead."

Immediate first aid procedures

Assessment and safety measures

Quickly assess consciousness and breathing without sudden movements (risk of cardiac arrest). Insulate from the cold : remove the victim from the cold environment, insulate them from the ground with a mattress, blankets, and dry clothing.

Safe heating techniques

Passive warming (mild hypothermia): wrap in dry blankets , hat, "sandwich" technique with survival blanket silver side towards skin.

External active warming : hand warmers wrapped in fabric (maximum 40°C) on the torso only. Never on the extremities (risk of heat shock).

Sweetened hot drinks are permitted if the person is conscious and able to swallow. Absolutely forbidden : alcohol, coffee, tobacco, and nothing orally if the person is unconscious.

Avoid fatal mistakes

• Never use sudden warming methods (hot bath, radiator)

• Never massage frozen extremities

• Never make sudden movements in a severely hypothermic patient

• Never drink alcohol "to warm up"

Essential equipment and prevention

Emergency equipment

Emergency blankets : retain 90% of body heat. Chemical hand warmers : provide gentle, prolonged heat; place on the torso only. Emergency sleeping bags offer superior insulation.

Active prevention

Multi-layer system : moisture-wicking base layer, insulating layer, wind/rain protection. Extremity protection : hat and gloves account for 40% of heat loss.

Recognizing the dangers : wind amplifies the effects of the cold. At 0°C with a 50 km/h wind speed, the perceived temperature is -15°C. Wet clothing loses 90% of its insulating properties.

Critical special cases

Infants

Babies do not shiver. Specific signs : cold and red skin, lethargy, refusal to feed. Warming : skin-to-skin contact, room temperature 25°C minimum.

Elderly people

Domestic hypothermia : misleading signs (confusion, falls) often wrongly attributed to dementia. Prevention : home temperature >19°C, regular monitoring.

Immersion

Cold water accelerates hypothermia 15 times more than air. Survival time : 15 minutes at 0°C, 30 minutes at 5°C. Get out of the water as an absolute priority.

Alert the emergency services

Criteria for life-threatening emergencies

Call 15 (SAMU) or 112 immediately if:

• Temperature <32°C
• Disturbances of consciousness
• Stopping of shivering in a person exposed to cold
• Cardiovascular signs
• Unconscious victim

Avoid transporting yourself if you have moderate/severe hypothermia: vibrations can trigger cardiac arrest.

Dangerous Myths

"Alcohol warms you up" : false and deadly. Alcohol accelerates heat loss. "Rubbing frozen limbs" : can cause serious injury. "Hot bath" : sudden rewarming can be fatal.

Hypothermia survival kit

Minimum contents : 2 survival blankets , 6 body warmers , low-temperature thermometer, emergency hat and gloves. Storage : vehicle, home, depending on your activities.

To know is already to begin saving

Hypothermia remains a largely unknown life-threatening emergency that claims lives every winter. Early recognition of the signs and the application of simple measures can save a life. This knowledge transforms every citizen into an essential link in the chain of survival.

Get trained, equip yourself, and raise awareness among those around you . Winter is approaching, and with it, the risk of hypothermia. When you encounter someone suffering from heat exhaustion, your preparation will make the difference between life and death.

Controlled hypothermia: when your knowledge becomes their chance of survival.