Hypothermia is an emergency condition that occurs when the body loses heat faster than it can produce it, causing the core body temperature to drop below 95°F (35°C). This dangerously low temperature impairs normal bodily functions, particularly in the brain and heart, and requires immediate, gentle intervention. Understanding the safest sequence of actions is paramount because the body’s systems become increasingly fragile as the temperature drops. The goal of first aid is to halt heat loss, initiate gradual rewarming, and stabilize the person while waiting for professional medical assistance.
Recognizing the Signs and Severity
Assessing the person’s condition is the first step, as the severity of hypothermia dictates the urgency and nature of the response.
Mild hypothermia occurs when the core temperature is between 90°F and 95°F (32°C and 35°C). It is characterized by vigorous shivering, which is the body’s attempt to generate heat through muscle activity. During this stage, the person may also exhibit signs of confusion, have slightly slurred speech, and appear lethargic.
As the core temperature drops further, the condition progresses to moderate hypothermia, typically between 82°F and 90°F (28°C and 32°C). In this stage, the person’s shivering often stops entirely, signaling that the body’s compensatory mechanisms are failing. They will likely experience difficulty moving, display poor coordination, and have noticeably slowed breathing and pulse.
If the temperature falls below 82°F (28°C), the person has severe hypothermia, which is life-threatening. They may lose consciousness, and their pulse and breathing can become so weak or irregular that they are barely detectable. It is a fundamental rule of cold-weather first aid that a person is never declared dead until they are warm and still deceased.
Immediate Safety and Isolation from Cold
The first and most important action is to call emergency services immediately upon suspicion of hypothermia, as professional medical care is always required. While waiting for help to arrive, the primary focus must be on isolating the person from the cold environment to prevent further heat loss. If the person is conscious, they should be moved gently to a warm, dry shelter, or at least shielded from wind and insulated from the cold ground with a blanket or other material.
It is necessary to remove all wet clothing—including hats, gloves, and socks—because water conducts heat away from the body significantly faster than air. If necessary, clothing should be cut away to minimize movement. Minimizing movement is critical because vigorous or jarring movements can trigger a potentially fatal cardiac arrhythmia.
After removing the wet items, the person should be covered with layers of dry material, such as blankets, towels, or dry clothing. Covering the head is also necessary, as a significant amount of heat can be lost from an uncovered scalp. The insulation should be layered around the person’s core, and they should be kept in a flat position to reduce strain on the circulatory system.
Gentle Rewarming Techniques
Rewarming must be done gradually and indirectly, focusing only on the core areas of the body to prevent complications. The safest method for applying external heat is by using warm compresses, warm water bottles, or dry heating pads applied exclusively to the neck, chest, armpits, and groin. These areas are where major arteries are close to the surface, allowing for efficient warming of the circulating blood.
Any source of external heat, such as a hot water bottle or chemical pack, must first be wrapped in a towel or blanket to prevent direct contact with the skin and avoid burns. For a conscious victim, offering a warm, sweetened, non-alcoholic, and non-caffeinated beverage, like broth or sweetened tea, can be beneficial. The sugar provides energy needed to fuel the body’s metabolic processes, including shivering, and the warmth offers some internal comfort.
In cases of mild hypothermia where the person is still actively shivering, skin-to-skin contact with a warm rescuer under a layer of dry blankets can be an effective passive rewarming technique. Monitor the person’s breathing and pulse while awaiting the arrival of medical professionals. The goal remains slow, steady core rewarming until definitive medical care can take over.
Actions to Strictly Avoid
Several common first-aid instincts are dangerous and must be strictly avoided when treating hypothermia. One of the most harmful actions is rubbing or massaging the extremities, which can force cold, acidic blood from the limbs back toward the heart. This sudden rush of cold blood can cause a life-threatening cardiac arrest, a phenomenon often referred to as “afterdrop.”
It is also dangerous to apply intense, direct heat sources, such as hot water, heating lamps, or a very hot bath. Rapid external warming can cause peripheral blood vessels to dilate suddenly, leading to a drop in blood pressure and potentially inducing shock or an irregular heartbeat. The rewarming process must remain moderate and focused on the core.
Never give a hypothermia victim alcohol or caffeinated drinks, even if they are warm. Alcohol causes vasodilation, increasing blood flow to the skin and accelerating heat loss. Caffeine acts as a diuretic, increasing dehydration. Never assume a person in severe hypothermia is dead; resuscitation efforts must be continued until a medical professional confirms death.