Hypothermia (Low Body Temperature) (2024)

What are the symptoms of hypothermia?

Hypothermia symptoms vary based on the severity of the condition. The stages of hypothermia include mild, moderate and severe.

Mild hypothermia

Mild hypothermia means your body temperature is between 95 F and 89.6 F (35 C and 32 C). Signs of mild hypothermia include:

• Shivering and chattering teeth.
• Exhaustion.
• Clumsiness, slow movements and reactions.
• Sleepiness.
• Weak pulse.
• Fast heart rate (tachycardia).
• Rapid breathing (tachypnea).
• Pale skin color.
• Confusion and poor judgment/loss of awareness.
• Excessive urination.
• Trouble speaking.

Moderate hypothermia

Moderate hypothermia means your body temperature is between 89.6 F and 82.4 F (32 C and 28 C). Signs of moderate hypothermia include:

• Slow down in breathing and heart rate.
• Slurred speech.
• Decline in mental function.
• Hallucinations.
• Decreased shivering.
• Bluish color to skin (cyanosis).
• Increased muscle stiffness.
• Dilated pupils.
• Abnormal heart rhythm.
• Decreased blood pressure.
• Weakened reflexes.
• Loss of consciousness.

Severe hypothermia

Severe hypothermia means your body temperature is less than 82.4 F (28 C). Signs of severe hypothermia include:

• Loss of shivering.
• Low blood pressure (hypotension).
• Fluid in lungs.
• Absence of reflexes.
• Complete muscle stiffness.
• Loss of voluntary motion.
• Low urine output (oliguria).
• Heart stops beating (cardiac arrest).
• Coma that may mimic death.
• Death.

What causes low body temperature (hypothermia)?

Hypothermia occurs after exposure to cold, wet or windy conditions. When you’re exposed to cold, your body expends energy to keep you warm. Eventually, with continued exposure to cold temperatures, your body uses up its stored energy and your body temperature begins to fall. You’re not able to warm yourself back up. Symptoms will progress from mild to severe with prolonged exposure.

While most cases of hypothermia occur at very cold temperatures, the condition can affect you even in cooler temperatures over 40 F (4.4 C) if you become chilled from sweat, rain or submersion in cold water. Hypothermia occurs under environmental conditions (wet, cool/cold or windy) that cause a person’s body to lose more heat than it generates.

Who is at risk for developing hypothermia?

Although anyone can get hypothermia, certain people, conditions and situations increase the risk of developing hypothermia. These include:

• Older people. The ability to control body temperature lessens with age. Older people also tend to expend less energy (which generates heat to keep your body warm) because they’re less active than younger people. Older people tend to have less fat to provide insulation as well.
• Young children. Children use more calories (energy) than adults and may use up their reserve while playing and not realize they’re cold. Children have more surface area for their size, which increases their heat loss.
• Babies. Infants lose body heat more easily than adults, don’t have the energy reserve to shiver to increase their body heat and can even become hypothermic if they sleep in a cold room. Signs of hypothermia in an infant include cold skin, bright red skin, inactivity/lack of energy and body temperature under 95 F (35 C). Babies have the highest surface area for their weight and lose heat the most rapidly.
• Inexperienced outdoor adventure seekers. This includes hikers, hunters and fishers who don’t have appropriate gear for the cold and wet conditions they may encounter.
• People who abuse alcohol or recreational drugs. Alcohol expands blood vessels, allowing heat to leave your skin surface more rapidly. Alcohol, as well as drug use, can impair a person’s ability to feel cold and/or not have good judgment about wearing appropriate clothing to match the weather conditions or coming inside when cold.
• People who don’t have a home. People without a place to live may not have or not choose indoor shelter options with heat. They also may not have clothing appropriate for the weather conditions.
• People with mental health conditions. People who have dementia or other intellectual impairment may lack the ability to judge weather conditions, may wander away from home and get lost, and may not wear appropriate clothing to stay warm for an extended time in cold weather.
• People with certain medical conditions may be more susceptible to cold temperatures. These conditions include hypothyroidism, hypoglycemia, hypopituitarism, shock, sepsis, anorexia nervosa, stroke, Parkinson’s disease, peripheral neuropathy and spinal cord injury.
• People taking certain medications. Medications that can impair your response to cold include sedatives, anesthetics, opioids, phenothiazine antipsychotics and clonidine.
• People participating in cold-weather sports. Sports like skiing often occur at low temperatures and happen in areas with unpredictable weather patterns. The activity level pre-disposes heat loss due to the activity involved and sweating. These sports can also expose participants to injury, and in severe instances, can lead to altered decision-making.

What are the complications associated with hypothermia?

If left untreated, hypothermia can lead to various medical conditions, including:

• Cardiac arrest.
• Liver damage.
• Kidney failure.
• Coma.
• Death.