Hypothermia

Hypothermia, defined as a core temperature of less than 35° C, may occur in healthy patients after acute cold exposure or in patients with medical or social conditions that limit adaptive mechanisms or temperature perception. Alcohol blunts temperature sensation in intoxicated patients and increases heat loss through vasodilation, thereby increasing the risk of severe hypothermia. Resuscitative measures, including establishment of airway control, in addition to rapid rewarming, are necessary for severe hypothermia. Arrhythmia treatment may be ineffective until core temperature is >32° C. Attempts to resuscitate patients in cardiac arrest should be continued until their core temperature is at least 35° C. Evaluation and treatment for possible infection or other conditions leading to hypothermia are required.

Causes

Hypothermia is possible in mild weather. Eg, if you get soaked in a rain shower and do not dry off properly soon afterwards, particularly if there is a cool wind. The water evaporating from you skin brings down your body temperature.

Some groups are at higher risk of hypothermia and some causes such as includes:

• Being outside without enough protective clothing in the winter.
• Falling overboard from a boat into cold water.
• Homeless people who are unable to find shelter.
• People with mental illnesses such as Alzheimer’s disease may not be able to recognise the symptoms of hypothermia or tell when they are cold.
• People who have fallen into cold water, which can cause the body’s core temperature to drop very quickly.
• People recovering from accidents.
• People taking sedatives, which can interfere with the body’s ability to regulate temperature.

Symptoms

Vary with degree of hypothermia and underlying medical condition

• Nausea
• Dizziness
• Chills
• Pruritus
• Dyspnea
• Confusion

Signs

Vary with degree of hypothermia and underlying medical condition

• Patient cool to touch
• Dysrhythmia
• Shivering
• Paradoxic undressing in early stages
• Hypotension
• Altered mental status
• Respiratory depression
• Decreased bowel sounds
• Apathy
• Abdominal rigidity
• Decreased level of consciousness
• Dysarthria
• Muscular rigidity
• Frostbite

Treatment

Hypothermia is treated by preserving body heat and preventing any more being lost. You should try to do the following if waiting for medical treatment:

• Change out of wet clothing and replaced with dry, warm clothing and blankets.
• Using hot water bottles
• Warm baths
• Heat packs placed under the arms and on the chest, neck, and groin.
• Have warm drinks.
• Once body temperature has increased, be sure to keep warm and dry.

In severe cases, if breathing and heartbeat have stopped, the person should not be considered dead until efforts have first been made by medical professionals to warm him or her.

The medical team will use heated intravenous fluids. The person may be wrapped with blankets in a warm room or put into a large tub of warm water. In severe or complicated cases of hypothermia, intravenous drug therapy may be used.