Healthy Living

What Causes Heat Exhaustion?

What Causes Heat Exhaustion?

Heat exhaustion is a condition that results from dehydration due to exposure to very high temperatures. Heat exhaustion is categorized into two types based on the underlying changes in the body – exhaustion due to depletion of water and exhaustion due to depletion of salt. When the condition results from depletion of water in the body, it is characterized by excessive thirst, fatigue and headache. When heat exhaustion is caused by depletion of salt in the body, nausea, vomiting, muscle cramps, and dizziness are seen as common symptoms. Heat exhaustion should be treated as soon as possible as it may lead to more serious and life threatening heat stroke.

Body temperature is controlled by hypothalamus, the part of the brain that controls thirst and hunger. Under normal conditions, the body cools by sweating. While working under high temperature conditions without replacing the body fluids periodically, the regulatory system may go haywire and the body produces more heat than what can be dissipated or released. This results in the symptoms of heat exhaustion. When left unattended, heat exhaustion may lead to heat stroke, a condition that affects brain and other vital organs and may also cause death.

The most common symptoms of heat exhaustion include:

  • Confusion
  • Change in the color of urine
  • Dizziness
  • Fainting
  • Fatigue
  • Headache
  • Muscle cramps
  • Sweating
  • Increase in heart beat rate
  • Nausea and vomiting

The major factors that affect the condition is heat index, a combined measure of temperature, relative humidity, and body heat. When the heat index increases above 90, the risk of heat exhaustion also increases considerably. The heat index increases while standing under full sunlight. Heat wave and air pollution increases the heat index and thus the risk of heat exhaustion.

Some of the other factors that increase the risk of heat exhaustion include:

  • Age – Small children and elders above the age of 65 years are more prone to this condition as the body adjusts to change of temperature at a slower rate than others.
  • Health conditions – Presence of diseases like heart, lung and kidney, obesity, hypertension, diabetes, sickle cell, sunburn and alcohol abuse increases the risk of getting heat exhaustion.
  • Certain medications – Diuretics, sedatives, certain drugs used in the treatment of high blood pressure, psychiatric conditions all enhance the risk of heat exhaustion.   

Some common methods to treat the condition include:

  • Drink plenty of fluid
  • Remove tight clothing
  • Have a cool shower
  • Apply ice towels