Hypothermie

Hypothermie is a medical condition in which the body's core temperature falls below the normal range, typically less than 35°C (95°F). It most often results from prolonged exposure to cold air or water, but can also occur due to malnutrition, illness, fatigue, alcohol or drug use, or certain medical conditions that impair heat production or conservation. Hypothermie can be accidental, occupational, or accidental rewarming failure after immersion.

Causes and risk factors include outdoor exposure in cold weather, immersion in cold water, wind chill, inadequate clothing or shelter, and situations that impair heat generation such as burns, trauma, or intoxication. Vulnerable groups include young children, elderly people, chronically ill individuals, and those who are intoxicated or dehydrated.

Symptoms vary with severity. Mild hypothermie (32–35°C) may present as shivering, rapid breathing, rapid heartbeat, confusion, and pale, cold skin. Moderate hypothermie (28–32°C) can cause slurred speech, drowsiness, loss of coordination, and apparent exhaustion. Severe hypothermie (below 28°C) may lead to a suspended or slowed mental state, markedly slowed heart rate, and loss of consciousness; the person may appear dead-like but still respond to gentle handling in some cases.

Diagnosis relies on measuring core temperature with appropriate devices (rectal or esophageal measurements are most accurate) and assessing clinical signs. Treatment focuses on safe rewarming and preventing complications. In the field, move the person to a warm environment, replace wet clothing with dry, insulate, and rewarm gradually with blankets and body-to-body heat if necessary. Avoid vigorous rubbing or heat sources on the extremities; provide warm drinks if conscious.

Medical care may involve passive external rewarming, active external rewarming, or active internal rewarming (such as warmed IV fluids or humidified oxygen) in a hospital setting. Prognosis depends on temperature, duration of exposure, and associated injuries; early recognition and appropriate rewarming improve outcomes. Prevention includes proper clothing, shelter, hydration, avoiding alcohol, and recognizing early signs in at-risk individuals.