Difference between Heat Stroke, Heat Exhaustion, and Heat Cramps

Published on September 8, 2015

Heat-related illnesses occur when there is prolonged exposure to heat or when there is excessive perspiration without adequate hydration. This means that there is a disproportionate loss of water and salt in the system, and an unusual increase in body temperature. The three most common heat-related illnesses are: heat stroke, heat exhaustion, and heat cramps. These three are discussed in detail in this article.

Definitions

Heat Stroke vs Heat Exhaustion vs Heat Cramps
Athlete with heat stroke

Heat Stroke or sunstroke is the worst type of heat-related illness because it can be life-threatening. This is characterized by body temperature higher than 105 degrees Fahrenheit or 40.6 degrees Celsius, complications with the central nervous system, nausea, seizures, confusion, disorientation, and loss of consciousness or coma. Heat stroke is a consequence of other milder forms of heat-related illnesses like heat fainting, heat exhaustion, and heat cramps. If left untreated it can cause damage to the brain and other internal organs. It is a must to call paramedics immediately and perform first aid treatment.

Heat exhaustion is less severe compared to heat stroke. Heat exhaustion can be classified as: water depletion and salt depletion. The former, water depletion, is characterized by excessive thirst, weakness, headache, and loss of consciousness. The latter, salt depletion, is characterized by nausea and vomiting, muscle cramps, and dizziness. Without adequate treatment, this can lead to heat stroke.

Heat cramps manifest as sporadic and spontaneous muscle cramps and spasms. They can occur during or after an intense workout. They can also happen when there is excessive sweating at elevated temperatures. Muscles of the legs and thigh, core muscles, and arm muscles are the most commonly affected areas of heat cramp. Among the three, this is the mildest.

Comparison Chart

Heat StrokeHeat ExhaustionHeat Cramps
Worst type of heat-related illness.Less severe compared to heat stroke.Mildest form of heat-related illness.
Primary symptom: body temperature higher than 105 degrees Fahrenheit or 40.6 degrees Celsius.Other symptoms include: warm and dry skin, fever, increased heart rate, shallow breathing, loss of appetite, nausea, vomiting, throbbing headache, dizziness, light-headedness, fatigue, confusion, muscle weakness or cramps, agitation, lethargy, stupor, lack of sweating, and in worst case scenarios, seizures, coma and death.Symptoms include: muscle cramps, pale and moist skin, fever, nausea, vomiting, diarrhoea, headache, dizziness, fatigue, weakness, anxiety, heavy sweating and rapid pulse.Symptoms include: painful cramps, particularly in the legs, red and moist skin and dark-colored urine.
First aid and treatment include: call an emergency medical service immediately or if possible take the patient to the nearest hospital; rest and staying in a cool and shady place; change to cool and comfortable clothes; fan the patient; drench skin with cool water; place ice bags or ice packs on armpits and groin area;if patient is capable, have them drink cold fluids, particularly water.First aid and treatment include: rest and staying in a cool and shady place; change to cool and comfortable clothes; drink sports drinks having ample ions.If symptoms persist take the patient to the nearest hospital; IV fluid may be necessary.First aid and treatment include: rest and staying in a cool and shady place; change to cool and comfortable clothes; drink sports drinks having ample ions, stretch cramped muscles.

Heat Stroke vs Heat Exhaustion vs Heat Cramps

What is the difference between heat stroke, heat exhaustion, and heat cramps? Let us compare the three in terms of severity, symptoms, first aid and treatment.

  • Among the three types of heat-related illness, the worst type would be heat stroke which can be fatal. Next to this is heat exhaustion. And the least serious would be heat cramps.
  • The primary symptom for heat stroke is a body temperature of at least 105 degrees Fahrenheit or 40.6 degrees Celsius. Other symptoms for heat stroke include warm and dry skin, fever, increased heart rate, shallow breathing, loss of appetite, nausea, vomiting, throbbing headache, dizziness, light-headedness, fatigue, confusion, muscle weakness or cramps, agitation, lethargy, stupor, and lack of sweating. In the worst case situation, seizures, coma and death can be seen in heat stroke patients.
    There are fewer symptoms seen in patients suffering heat exhaustion. The symptoms include muscle cramps, pale and moist skin, fever, nausea, vomiting, diarrhoea, headache, dizziness, fatigue, weakness, anxiety, heavy sweating, and rapid pulse.
    As for heat cramps, the symptoms observed are painful cramps particularly in the legs or muscle group that exerted energy, red and moist skin, and dark-colored urine, which is the primary sign of dehydration.
  • First aid and treatment for heat stroke must be given urgently since this can be fatal. Call an emergency medical service immediately, or if possible take the patient to the nearest hospital. If waiting for an emergency medical service let the patient rest and stay in a cool and shady place; if there are extra clothes change the outfit to something cool and comfortable; fan the patient allowing cool air to circulate around them; and drench the skin with cool water or place ice bags or ice packs on armpits and groin area. These areas have ample blood supply close to the skin, thus placing ice bags there can decrease body temperature. If the patient is capable allow them to drink cold fluids, particularly water. Do not give them alcohol or any diuretic product; these would lead to more water loss.
    For heat exhaustion, allow the patient to rest and stay in a cool and shady place, change the outfit to something cool and comfortable, and let the patient drink sports drinks having ample  ions. If symptoms persist take the patient to the nearest hospital where IV fluid may be judged to be necessary. If the patient is not treated adequately, heat stroke may follow.
    Last but not least, heat cramps are treated in the same way: allow the patient to rest and stay in a cool and shady place, change the outfit to something cool and comfortable, and drink ample  fluids.  Stretch the affected cramped muscles.

Video

The following videos could help you better understand the difference between heat stroke, heat exhaustion and heat cramps.

The first video discusses the difference between heat stroke and heat exhaustion:

The next video discusses heat cramps.