Understanding Hypothermia
Hypothermia is a medical emergency that occurs when your body loses heat faster than it can produce it, causing a dangerously low body temperature. A normal body temperature is around 98.6°F (37°C), but for hypothermia, the core body temperature drops below 95°F (35°C). While most common in cold weather, it can occur in milder temperatures if a person is wet from rain, sweat, or submersion in cold water. It is a life-threatening condition that demands immediate attention. Acting quickly to recognize the signs is the first step toward saving a life.
Visual and Physical Assessment: The First Step
When you suspect someone has been exposed to the cold for a prolonged period, a visual and physical assessment is the first step. The signs can vary significantly depending on the severity of the condition. Pay close attention to their mental state and physical symptoms, as judgment can be impaired, and they may not realize they are in danger.
Look for physical indicators
- Shivering: This is the body's automatic defense against cold. However, it is an early sign. In severe cases, shivering may stop completely as the body's energy reserves are depleted. The absence of shivering, despite continued cold exposure, is a grave sign.
- Pale, Cold Skin: The skin may feel cold to the touch. For infants, a specific sign is bright red, cold skin. As hypothermia progresses, the skin can become pale or bluish.
- Slow, Shallow Breathing: As the body's systems slow down, the breathing rate will decrease.
- Weak Pulse: The heart rate slows down to conserve energy. The pulse may become very faint and difficult to detect.
- Fumbling Hands and Weakness: Fine motor skills are often impaired early on, causing fumbling, clumsiness, and a lack of coordination.
- Drowsiness or Exhaustion: The person may appear very tired, lethargic, or drowsy. In severe cases, they may become unresponsive or lose consciousness entirely.
Check for changes in mental state
- Confusion or Memory Loss: The cold affects brain function, leading to confusion, memory loss, and poor judgment. This is one of the most dangerous symptoms, as the person may not be aware of their own condition.
- Slurred Speech: The person may have difficulty speaking clearly or be mumbling.
- Apathy: They may show a lack of interest in their situation and seem unconcerned about their cold state.
- Paradoxical Undressing: In severe hypothermia, a person may become disoriented and begin to remove their clothing. This is a very serious sign that requires immediate medical help.
Using a Thermometer for Confirmation
While visual signs are important, the most definitive way to check for hypothermia is by measuring the body's core temperature. If a temperature below 95°F (35°C) is recorded, it confirms hypothermia.
- Electronic Rectal Thermometer: Health professionals diagnose hypothermia by measuring the body temperature with an electronic rectal thermometer.
- Low-Reading Thermometers: Most standard thermometers do not read low enough temperatures for severe hypothermia. Special low-reading thermometers are necessary for very low core temperatures.
- Accuracy Note: Measuring the temperature orally or in the armpit is not reliable for diagnosing hypothermia. These readings are often significantly lower than the core temperature.
Stages of Hypothermia: A Comparison
The severity of hypothermia is often categorized into mild, moderate, and severe stages, each with distinct symptoms. Recognizing the stage can help you determine the urgency and appropriate response.
| Feature | Mild Hypothermia (90°F–95°F) | Moderate Hypothermia (82°F–90°F) | Severe Hypothermia (<82°F) |
|---|---|---|---|
| Shivering | Vigorous shivering. | Shivering stops or becomes intermittent. | Shivering stops completely. |
| Mental Status | Alert but may be confused, apathetic, or have impaired judgment. | Stupor, memory loss, more pronounced confusion. | Unconsciousness, unresponsive. Pupils may be dilated and fixed. |
| Coordination | Clumsiness, fumbling hands, difficulty with fine motor skills. | Ataxia (loss of coordination), slurred speech. | Rigidity, loss of reflexes, appears lifeless. |
| Vital Signs | Heart rate and breathing may be faster. | Slowed heart rate and breathing (bradycardia, bradypnea). | Very slow or absent pulse and breathing. Possible cardiac arrest. |
| Other Signs | Pale, cold skin. | Paradoxical undressing may occur. | Fixed pupils, risk of ventricular fibrillation and asystole. |
What to Do If You Suspect Hypothermia
If you believe someone has hypothermia, prompt action is critical. First aid measures are crucial while waiting for emergency medical services.
- Call 911 immediately. Hypothermia is a medical emergency that can quickly become life-threatening.
- Move the person gently to a warm, dry place. If going indoors isn't possible, protect them from wind and insulate them from the cold ground with blankets or jackets. Avoid vigorous or jarring movements, as this can trigger cardiac arrest.
- Remove any wet clothing. Replace it with warm, dry blankets or coats. If necessary, cut away clothing to minimize movement.
- Warm the body's core. Focus on the chest, neck, head, and groin. Use blankets, an electric blanket, or warm, dry compresses wrapped in a towel. You can also use skin-to-skin contact.
- Provide warm, sweet drinks if they are alert. If the person is conscious and can swallow, offer warm (not hot) beverages to help raise their body temperature. Do not give alcohol or caffeinated drinks. Do not attempt to give anything to an unconscious person.
- Perform CPR if necessary. If the person appears unresponsive, is not breathing, or has no pulse, begin CPR if you are trained. Continue CPR until medical help arrives or the person responds. In cold weather emergencies, a person isn't considered dead until they are "warm and dead".
- Do not apply direct heat. Avoid using hot water, heating pads, or lamps. This can damage the skin and stress the heart.
Staying Vigilant and Prepared
Preventing hypothermia is always the best strategy. In cold weather, ensure everyone is dressed in layers, avoids cotton, and stays dry. Pay special attention to vulnerable individuals, including the very young, the elderly, those with chronic illnesses, and those who may be under the influence of alcohol or drugs. Carrying extra warm, dry clothing is wise for any extended time outdoors.
For more information on first aid and emergency preparedness, please consult resources from the American Red Cross Hypothermia Guide.
Conclusion: A Quick Guide to Action
Knowing how to check if someone has hypothermia involves being observant, acting quickly, and prioritizing safety. Look for key symptoms like uncontrolled shivering, confusion, slurred speech, or pale, cold skin. In severe cases, the person may become unresponsive and stop shivering entirely. If their core body temperature is below 95°F, it is a medical emergency. Move them to warmth, remove wet clothes, warm their core gently, and call for help immediately. Being aware of the signs and knowing the correct first aid steps can make all the difference.
