Temperature Exposure

The body temperature is a necessary element required for survival. - Sam Veda

Heat Related Illnesses

Prolonged or intense exposure to hot temperatures can cause heat related illnesses. Heat cramps, heat exhaustion, and heat stroke (also known as sun stroke) all occur when your body cannot cool itself adequately. But each is slightly different.

Heat Cramps

Heat cramps are the intermittent, involuntary spasm of muscles they can strike when the body loses excessive amounts of fluids and salt. This deficiency, accompanied by the loss of other essential nutrients such as potassium and magnesium, typically occurs during heavy exertion.

Heat cramps usually go away on their own, but treatments include:

Stop the activity being performed.
Rest in a cool place.
Drink plenty of fluids mixed with salt.
Gently stretch the muscles that are cramping.

Salt tablets by themselves should not be used. They can cause stomach upset and don't adequately replace fluid volume lost.

Heat Exhaustion

Occurs when the body loses large amounts of water and salt through excessive sweating, particularly through hard physical labor or exercise. This loss of essential fluids can disturb circulation and interfere with brain function. There are two types of heat exhaustion:

  • Water depletion. Signs include excessive thirst, weakness, headache, and loss of consciousness.
  • Salt depletion. Signs include nausea and vomiting, frequent muscle cramps, and dizziness.

Common Symptoms

Dark-colored urine (sign of dehydration)

Muscle cramps
Pale skin
Profuse sweating
Rapid heartbeat


If you, or anyone else, has symptoms of heat exhaustion, it's essential to immediately get out of the heat and rest, preferably in an air-conditioned room. If you can't get inside, try to find the nearest cool and shady place.

Other recommended strategies include:

Drink plenty of fluid (avoid caffeine and alcohol).
Remove any tight or unnecessary clothing.
Take a cool shower, bath, or sponge bath.
Apply other cooling measures such as fans or ice towels.

Although heat exhaustion isn't as serious as heat stroke, it isn't something to be taken lightly.

If such measures fail to provide relief within 30 minutes, contact a doctor because untreated heat exhaustion without proper intervention, can progress to heat stroke.

Risk Factors for Heat Exhaustion

Heat exhaustion is strongly related to the heat index, which is a measurement of how hot you feel when the effects of relative humidity and air temperature are combined. A relative humidity of 60% or more hampers sweat evaporation, which hinders your body's ability to cool itself.

Heat Index Chart

Heat Stroke

The most serious of the heat-related illnesses, occurs when the body suffers from long, intense exposure to heat and loses its ability to cool itself. Heat stroke often occurs as a progression from milder heat-related illnesses such as heat cramps, and heat exhaustion. But it can strike even if you have no previous signs of heat injury. As your body works to cool itself under extreme or prolonged heat, blood rushes to the surface of your skin. As a result, less blood reaches your brain, muscles, and other organs. This can interfere with both your physical strength and your mental capacity, and in some cases can damage the brain and other vital organs, and even cause death.


The hallmark symptom of heat stroke is a core body temperature above 105 degrees Fahrenheit. But fainting may be the first sign.

Other symptoms may include:

Throbbing headache
Dizziness and light-headedness
Lack of sweating despite the heat
Red, hot, and dry skin
Muscle weakness or cramps
Nausea and vomiting

Rapid heartbeat, which may be either strong or weak
Rapid, shallow breathing
Behavioral changes such as confusion, disorientation, or staggering


Call emergency services immediately.

Move the person to an air-conditioned environment - or at least a cool, shady area -- and remove any unnecessary clothing.
Fan air over the patient while wetting his or her skin with water from a sponge or garden hose.
Apply ice packs to the patient's armpits, groin, neck, and back.
Immerse the patient in a shower or tub of cool water, or an ice bath.

Cold Related Illnesses

At very cold temperatures, the most serious concern is the risk of hypothermia or dangerous overcooling of the body. Another serious effect of cold exposure is frostbite or freezing of the exposed extremities

It's easy to get cold quickly if you are outside in wet, windy, or cold weather. Cold temperature exposure can also happen if you spend time in a dwelling that are not well heated. Cold stress occurs by driving down the skin temperature and eventually the internal core body temperature. This may lead to serious health problems, and may cause tissue damage, and possibly death.

Some of the risk factors that contribute to
cold stress are:

Dressing improperly
Poor physical conditioning

How does the body react to cold conditions?

In a cold environment, most of the body's energy is used to keep the internal core temperature warm. Over time, the body will begin to shift blood flow from the extremities (hands, feet, arms, and legs) and outer skin to the core (chest and abdomen). This shift allows the exposed skin and the extremities to cool rapidly and increases the risk of frostbite and hypothermia.


Hypothermia occurs when body heat is lost faster than it can be replaced and the normal body temperature (98.6 F) drops to less than 95 F. Hypothermia is most likely at very cold temperatures, but it can occur even at cool temperatures (above 40 F), if a person becomes chilled from rain, sweat, or submersion in cold water.

Mild symptoms:

Begin to shiver.

Moderate to Severe symptoms:

As the body temperature continues to fall, shivering will stop.
Lose coordination.
Pupils become dilated
Pulse and breathing become slowed.
Loss of consciousness can occur.


Call emergency services immediately

Move the victim to a warm, dry area.
Remove wet clothes and replace with dry clothes
Cover the body, including the head and neck, with layers of blankets; and with a vapor barrier (e.g. tarp, garbage bag). Do not cover the face.

If medical help is more than 30 minutes away:

Give warm sweetened drinks if alert (no alcohol), to help increase the body temperature.
Place warm bottles or hot packs in armpits, sides of chest, and groin.


Frostbite is an injury to the body that is caused by freezing of the skin and underlying tissues. The lower the temperature, the more quickly frostbite will occur. Frostbite typically affects the extremities, particularly the feet and hands. Amputation may be required in severe cases.


Reddened skin develops gray/white patches.
Numbness in the affected part.
Feels firm or hard.
Blisters may occur in the affected part, in severe cases.


Windchill Chart

Follow the recommendations described above for hypothermia.
Do not rub the affected area to warm it.
Do not apply snow/water.
Do not break blisters.
Loosely cover and protect the area from contact.
Do not try to rewarm the frostbitten area before getting medical help; for example, do not place in warm water. If a frostbitten area is rewarmed and gets frozen again, more tissue damage will occur. It is safer for the frostbitten area to be rewarmed by medical professionals.
Give warm sweetened drinks, if the person is alert. Avoid drinks with alcohol.

Immersion/Trench foot

Trench Foot or immersion foot is caused by prolonged exposure to wet and cold temperatures. It can occur at temperatures as high as 60 F if the feet are constantly wet. Non-freezing injury occurs because wet feet lose heat 25-times faster than dry feet. To prevent heat loss, the body constricts the blood vessels to shut down circulation in the feet. The skin tissue begins to die because of a lack of oxygen and nutrients and due to the buildup of toxic products.


Redness of the skin.


Seek medical assistance as soon as possible.
Remove the shoes and wet socks.
Dry the feet.