Hypothermia
Hypothermia
Hypothermia occurs when a person's body temperature falls below 35 degrees Celsius. The systems that make up the human body are designed to keep the body at a consistent core temperature of 37 degrees Celsius. It is a common mistake to think that hypothermia can only occur in subzero temperatures. In fact, hypothermia most commonly occurs between temperatures of 0 to 10 degrees Celsius. Also, another cause of hypothermia can be certain medical conditions. For example, people who are lying immobile after a stroke or taking drugs have a risk of becoming hypothermic.
Common situations that can cause hypothermia:
These situations cause the body to lose more heat than it can generate.
Warning Signs
The first warning sign of hypothermia is uncontrollable shivering. The person stops shivering when they progress into severe hypothermia. The person may fall into a coma as the body temperature falls below 32 °C.
Once the brain cools to around 30 °C, the structure that regulates body temperature (hypothalamus) stops working. The person’s breathing and heart beat slows severely until it becomes undetectable. The heart no longer pumps blood effectively and the body is starved of oxygen. This is eventually fatal without prompt treatment. However, people with severe hypothermia can still demonstrate a great ability to recover if they are treated as quickly as possible.
Stages of Hypothermia:
First Aid for all cases:
First Aid for severe hypothermia:
Diagram of the symptoms of hypothermia:
Hypothermia occurs when a person's body temperature falls below 35 degrees Celsius. The systems that make up the human body are designed to keep the body at a consistent core temperature of 37 degrees Celsius. It is a common mistake to think that hypothermia can only occur in subzero temperatures. In fact, hypothermia most commonly occurs between temperatures of 0 to 10 degrees Celsius. Also, another cause of hypothermia can be certain medical conditions. For example, people who are lying immobile after a stroke or taking drugs have a risk of becoming hypothermic.
Common situations that can cause hypothermia:
- Prolonged exposure to cold conditions
- Being in cold water for a long time
- Spending excessive time in wet clothes
- Lying immobile in cool air or on a cold surface
These situations cause the body to lose more heat than it can generate.
Warning Signs
The first warning sign of hypothermia is uncontrollable shivering. The person stops shivering when they progress into severe hypothermia. The person may fall into a coma as the body temperature falls below 32 °C.
Once the brain cools to around 30 °C, the structure that regulates body temperature (hypothalamus) stops working. The person’s breathing and heart beat slows severely until it becomes undetectable. The heart no longer pumps blood effectively and the body is starved of oxygen. This is eventually fatal without prompt treatment. However, people with severe hypothermia can still demonstrate a great ability to recover if they are treated as quickly as possible.
Stages of Hypothermia:
- Feeling cold
- Cool, pale skin
- Shivering
- Loss of concentration, poor judgement
- Loss of control over fine motor coordination – for example, the muscles of the fingers
- Drowsiness
- Lethargy
- Confusion, irritability
- Dizziness
- Difficulty breathing
- Loss of physical coordination, unsteady on feet
- Stops shivering eventually
- Slurred speech, speech difficulty
- Slowed breathing
- Dilated pupils
- Coma
- Death.
First Aid for all cases:
- Don’t massage or rub the person – and do not allow them to help you. Keep them still or they risk a heart attack. If they move, the muscular activity will pump cold blood from their arms and legs into the central circulation and cause their core temperature to drop even more. This is one of the most important things to remember in this situation.
- Move the person out of the cold – if this is not possible, protect them from wind, cover their head and insulate their body from the cold ground.
- Remove wet clothing – replace with a dry covering, preferably warm. Cover the person’s head.
- Try to warm the person – but do not apply direct heat. Apply warm compresses to the neck, chest wall and groin. Do not use hot water, a heating pad or a heating lamp to warm the person. Do not attempt to warm the arms and legs – this will send cold blood back to the heart, causing body temperature to drop further.
- Share body heat – to warm the person’s body, remove your clothing and lie next to the person, making skin-to-skin contact. Then cover both bodies with a blanket or get into a sleeping bag if possible.
- Don’t give alcohol – it lowers the body’s ability to retain heat. If the person is alert and is able to swallow, have them drink warm, non-alcoholic beverages. Do not offer liquids if vomiting.
- Do not leave the person alone – stay with them at all times.
- Continue to monitor the person's breathing – if the person’s breathing stops, start cardiopulmonary resuscitation (CPR) immediately if you are trained. If unsure, dial triple zero (000) and the operators will advise you what to do. Continue CPR until the person starts breathing on their own or until medical assistance arrives.
- Don’t assume the person is dead – CPR can be lifesaving for a person with severe hypothermia who may appear to be dead. They may not be breathing, have no pulse, be cold to touch, have fixed pupils and be rigid – but they may still be alive.
First Aid for severe hypothermia:
- In an emergency, call triple zero (000).
- While waiting for help to arrive, monitor the person’s breathing. If they have severe hypothermia, their breathing may become dangerously slow or shallow or they may cease breathing.
- Begin cardiopulmonary resuscitation (CPR) immediately if the person shows no signs of life; that is, if they are not breathing normally, are unconscious or unresponsive, or not moving.
Diagram of the symptoms of hypothermia:
Hyperthermia
Hyperthermia
Hyperthermia is the general name given to a variety of heat-related illnesses. Regardless of extreme weather conditions, the healthy human body keeps a steady temperature of 98.6 degrees Fahrenheit. In hot weather or during vigorous activity, the body perspires. As this perspiration evaporates from the skin, the body is cooled. If challenged by long periods of intense heat, the body may lose its ability to respond efficiently. When this occurs, a person may experience hyperthermia. In other words, hyperthermia occurs when body metabolic heat production or environmental heat load exceeds normal heat loss capacity or when there is impaired heat loss.
Causes
Besides hypothermia being caused by overheating, it can also be caused by health conditions such as:
Other factors include being substantially overweight or underweight, and drinking alcoholic beverages.
Lifestyle factors include:
Signs and Symptoms
The two most common forms of hyperthermia are heat exhaustion and heat stroke. Of the two, heat stroke is especially dangerous and requires immediate medical attention.
Heat stress occurs when a strain is placed on the body as a result of hot weather.
Heat fatigue is a feeling of weakness brought on by high outdoor temperature. Symptoms include cool, moist skin and a weakened pulse. The person many feel faint.
Heat syncope is a sudden dizziness experienced after exercising in the heat. The skin appears pale and sweaty but is generally moist and cool. The pulse is weakened and the heart rate is usually rapid. Body temperature is normal.
Heat cramps are painful muscle spasms in the abdomen, arms or legs following strenuous activity. Heat cramps are caused by a lack of salt in the body.
Heat exhaustion is a warning that the body is getting too hot. The person may be thirsty, giddy, weak, uncoordinated, nauseated and sweating profusely. The body temperature is normal and the pulse is normal or raised. The skin is cold and clammy.
Heat stroke can be life-threatening and victims can die. A person with heat stroke usually has a body temperature above 104 degrees Fahrenheit. Other symptoms include confusion, combativeness, bizarre behavior, faintness, staggering, strong and rapid pulse, and possible coma. High body temperature is capable of producing irreversible brain damage.
First Aid for Hyperthermia
Heat Exhaustion:
Heat Stroke:
Hyperthermia is the general name given to a variety of heat-related illnesses. Regardless of extreme weather conditions, the healthy human body keeps a steady temperature of 98.6 degrees Fahrenheit. In hot weather or during vigorous activity, the body perspires. As this perspiration evaporates from the skin, the body is cooled. If challenged by long periods of intense heat, the body may lose its ability to respond efficiently. When this occurs, a person may experience hyperthermia. In other words, hyperthermia occurs when body metabolic heat production or environmental heat load exceeds normal heat loss capacity or when there is impaired heat loss.
Causes
Besides hypothermia being caused by overheating, it can also be caused by health conditions such as:
- poor circulation
- inefficient sweat glands, and changes in the skin caused by the normal aging process
- heart, lung and kidney diseases as well as any illness that causes general weakness or fever, high blood pressure or other conditions that require changes in diet
Other factors include being substantially overweight or underweight, and drinking alcoholic beverages.
Lifestyle factors include:
- unbearably hot living quarters
- lack of transportation - which prevents people from seeking respite from the heat in shopping malls, movie houses, and libraries
- overdressing - because they may not feel the heat, older people may not dress appropriately in hot weather
- visiting overcrowded places - trips should be scheduled during non-rush hour times
- not understanding weather conditions - older persons at risk should stay indoors on especially hot days.
Signs and Symptoms
The two most common forms of hyperthermia are heat exhaustion and heat stroke. Of the two, heat stroke is especially dangerous and requires immediate medical attention.
Heat stress occurs when a strain is placed on the body as a result of hot weather.
Heat fatigue is a feeling of weakness brought on by high outdoor temperature. Symptoms include cool, moist skin and a weakened pulse. The person many feel faint.
Heat syncope is a sudden dizziness experienced after exercising in the heat. The skin appears pale and sweaty but is generally moist and cool. The pulse is weakened and the heart rate is usually rapid. Body temperature is normal.
Heat cramps are painful muscle spasms in the abdomen, arms or legs following strenuous activity. Heat cramps are caused by a lack of salt in the body.
Heat exhaustion is a warning that the body is getting too hot. The person may be thirsty, giddy, weak, uncoordinated, nauseated and sweating profusely. The body temperature is normal and the pulse is normal or raised. The skin is cold and clammy.
Heat stroke can be life-threatening and victims can die. A person with heat stroke usually has a body temperature above 104 degrees Fahrenheit. Other symptoms include confusion, combativeness, bizarre behavior, faintness, staggering, strong and rapid pulse, and possible coma. High body temperature is capable of producing irreversible brain damage.
First Aid for Hyperthermia
Heat Exhaustion:
- lie the victim down
- loosen and remove excessive clothing
- moisten the skin with a moist cloth or atomiser spray cool by fanning
- give water to drink if fully conscious
- call for an ambulance (Dial Triple Zero - 000)
- keep in the shade.
Heat Stroke:
- call for an ambulance (Dial Triple Zero - 000)
- resuscitate following ARC Basic Life Support Flow Chart Guideline 8
- place the victim in a cool environment
- moisten the skin with a moist cloth or atomiser spray and fan repeatedly
- apply wrapped ice packs to neck, groin and armpits
Video on first aid for hyperthermia and hypothermia: