Hyperthermia
Definition
Hyperthermia is the general name given to a variety of heat-related illnesses.
Description
Warm weather and outdoor activity go hand in hand. However, it is important for older people to take action to avoid the severe health problems often caused by hot weather.
Causes
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.
Health Factors That Increase Risk
The temperature does not have to hit 100 degrees for a person to be at risk. Both one's general health and/or lifestyle may increase a person's chance of suffering a heat-related illness.
Health factors which may increase risk include:
Other factors include being substantially overweight or underweight, and drinking alcoholic beverages.
Lifestyle factors that can increase risk are:
SymptomsThe 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 delirium or coma. High body temperature is capable of producing irreversible brain damage.
DiagnosisDiagnosis is based on the medical history (including symptoms) and physical exam.
TreatmentIf the victim is exhibiting signs of heat stroke, emergency assistance should be sought immediately. Without medical attention, heat stroke can be deadly.
Heat exhaustion may be treated in several ways:
Hyperthermia is the general name given to a variety of heat-related illnesses.
Description
Warm weather and outdoor activity go hand in hand. However, it is important for older people to take action to avoid the severe health problems often caused by hot weather.
Causes
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.
Health Factors That Increase Risk
The temperature does not have to hit 100 degrees for a person to be at risk. Both one's general health and/or lifestyle may increase a person's chance of suffering a heat-related illness.
Health factors which may increase risk include:
- 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 feverhigh blood pressure or other conditions that require changes in diet
Other factors include being substantially overweight or underweight, and drinking alcoholic beverages.
Lifestyle factors that can increase risk are:
- 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.
SymptomsThe 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 delirium or coma. High body temperature is capable of producing irreversible brain damage.
DiagnosisDiagnosis is based on the medical history (including symptoms) and physical exam.
TreatmentIf the victim is exhibiting signs of heat stroke, emergency assistance should be sought immediately. Without medical attention, heat stroke can be deadly.
Heat exhaustion may be treated in several ways:
- get the victim out of the sun into a cool place, preferably one that is air conditioned
- offer fluids but avoid alcohol and caffeine - water and fruit juices are best
- encourage the individual to shower and bathe, or sponge off with cool water
- urge the person to lie down and rest, preferably in a cool place
Hypothermia
Summary
Hypothermia occurs when the body's temperature falls below 35 °C. Severe hypothermia can be fatal without prompt medical treatment. Symptoms of hypothermia include feeling cold, pale skin, shivering, loss of concentration, drowsiness, confusion, dizziness, slurred speech, dilated pupils and slowed breathing. First aid for hypothermia includes keeping the person still and not massaging or rubbing the affected person.
A person can also become hypothermic as a result of some medical conditions. People who lie immobile following a stroke or after taking drugs, for example, can become cold in a surprisingly short time.
Some situations can cause the body to lose more heat than it can generate. These situations can include:
Signs and symptoms of hypothermia
The first warning sign of hypothermia is uncontrollable shivering. The person stops shivering as 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 demonstrate an amazing capacity to recover if managed correctly.
Stages of hypothermia symptoms
The symptoms of hypothermia can progress slowly and people are often not aware they need medical help. The stages can include:
Factors that may increase a person’s susceptibility to hypothermia include:
Mild hypothermia (32–35 °C body temperature) is usually easy to treat. However, the risk of death increases as the core body temperature drops below 32 °C. If core body temperature is lower than 28 °C, the condition is life-threatening without immediate medical attention. Under this temperature, a person will be very cold to touch, unresponsive, rigid, not breathing, have no pulse, and their pupils will be fixed (they will not respond to light changes). They will appear to be dead but they may not be.
First aid for severe hypothermia
First aid steps for severe hypothermia include:
First aid for all cases of hypothermia
These first aid tips apply to all stages of hypothermia:
Hypothermia occurs when the body's temperature falls below 35 °C. Severe hypothermia can be fatal without prompt medical treatment. Symptoms of hypothermia include feeling cold, pale skin, shivering, loss of concentration, drowsiness, confusion, dizziness, slurred speech, dilated pupils and slowed breathing. First aid for hypothermia includes keeping the person still and not massaging or rubbing the affected person.
A person can also become hypothermic as a result of some medical conditions. People who lie immobile following a stroke or after taking drugs, for example, can become cold in a surprisingly short time.
Some situations can cause the body to lose more heat than it can generate. These situations can include:
- 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
Signs and symptoms of hypothermia
The first warning sign of hypothermia is uncontrollable shivering. The person stops shivering as 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 demonstrate an amazing capacity to recover if managed correctly.
Stages of hypothermia symptoms
The symptoms of hypothermia can progress slowly and people are often not aware they need medical help. The stages can include:
- 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.
Factors that may increase a person’s susceptibility to hypothermia include:
- Infancy – children lose heat more quickly than adults, mostly through their head. This is particularly so for babies, who must be protected from the cold
- Old age – people taking medications or suffering other health problems may be less able to regulate their own body heat or detect that they are being affected by temperature. They may also be less able to move about or make necessary changes to help
- Heart problems
- Circulatory system disorders
- A thin body or low body fat
- Hunger
- Fatigue
- Alcohol
- Cigarette smoking
- Drugs
- Dehydration
- Physical exertion.
Mild hypothermia (32–35 °C body temperature) is usually easy to treat. However, the risk of death increases as the core body temperature drops below 32 °C. If core body temperature is lower than 28 °C, the condition is life-threatening without immediate medical attention. Under this temperature, a person will be very cold to touch, unresponsive, rigid, not breathing, have no pulse, and their pupils will be fixed (they will not respond to light changes). They will appear to be dead but they may not be.
First aid for severe hypothermia
First aid steps for severe hypothermia include:
- 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.
First aid for all cases of hypothermia
These first aid tips apply to all stages of hypothermia:
- 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.
- 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.
- Continually monitor breathing – if the person’s breathing stops, start cardiopulmonary resuscitation (CPR) immediately if you are trained. If unsure, dial triple zero (000) – 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.