With winter here, the risk for hypothermia remains high. However, according to Dr Robyn Holgate, ER24’s chief medical officer, you don’t have to be freezing for hypothermia to develop. There are many ways we can lose heat from the body.
What is hypothermia?
Hypothermia is a condition where the body loses heat faster than the body can produce it.
How does hypothermia occur?
Accidental hypothermia: This is the unintentional drop in body temperature to less than 35°C when the body’s usual responses to cold begin to fail. Examples of those affected include someone that is inadequately prepared, for example, the elderly or homeless, someone caught in a winter storm, or even an outdoor sports enthusiast.
Intentional: post-trauma or after a cardiac arrest, which we generally call therapeutic hypothermia.
There are many ways where we can lose heat from the body, for example:
Convection when you have wet clothing on or a fan to cool down;
Conduction which is the transfer of body heat to other objects (for example sitting on a cold metal chair);
Evaporation which is responsible for about 20 to 30% of heat loss in temperate conditions, losing heat through the conversion of water to gas (evaporation of sweat);
Radiation is a form of heat loss through infrared rays. This involves the transfer of heat from one object to another, with no physical contact required. For example, the sun transfers heat to the earth through radiation.
It is important to note that hypothermia is not just having a low body temperature or someone who is shivering. Heat loss in cold, wet weather increases the risk for hypothermia and injury. Heat loss can occur in warm temperatures through conduction. Swimming or sitting in cool or cold water can cause the body to lose heat very quickly and increase the risk for hypothermia.
According to Dr Holgate, there are different stages of hypothermia. She explains that “medically we classify hypothermia as a temperature less than 35 degree Celsius. Our normal body temp is in the region of about 37 degrees.”
Mild hypothermia is the initial phase to stop the cold where you might shiver, have a fast heartbeat, have rapid breathing and blood vessel constriction occurs.
Moderate hypothermia is where your body experiences a decreased heart rate, a changed level of consciousness, decreased respiratory rate, dilated pupils and decreased gag reflex.
Severe hypothermia is when there is usually no perceptible breathing, the person is in a coma, they have non-reactive pupils, they don’t pass any urine, and they sometimes present with pulmonary oedema.
Treatment for hypothermia varies according to severity.
First aid guidelines for the treatment of hypothermia:
When you’re helping a person with hypothermia, handle him or her gently.
Move the person out of the cold to a warm, dry location sheltering them from the wind.
If the person is wearing wet clothing, remove it.
Cover the person with dry blankets and don’t forget to cover their heads too. Ensure they lie on a blanket or warm surface. If you have first aid, make use of warm compresses around the groin and chest area to provide warmth for the patient.
Provide warm beverages if the person is alert and able to drink fluids.
Monitor the patient’s breathing. A person with severe hypothermia may appear unconscious, with no apparent signs of a pulse or respiration. If the person’s breathing has stopped or seems dangerously low or shallow, begin CPR.
Within the Emergency Medical Service (EMS), paramedics use a rescue blanket as well as a standard blanket to warm patients up. The rescue blanket can prevent heat loss through convection or radiation. The standard blanket can prevent heat loss through conduction and convection. They may use passive or active rewarming techniques depending on the severity of hypothermia. These methods may include, blood rewarming, warm intravenous fluid use, airway rewarming and irrigation techniques.
Seniors, children and the homeless are at significant risk of developing hypothermia this winter. Try and remain indoors and keep yourself warm. If a patient shows symptoms of mild hypothermia make sure they stay inside and keep warm so that the person’s condition does not worsen. Prevention remains better than cure.
Medical attention must be sought immediately if someone appears to be suffering from hypothermia and is becoming lethargic and confused.