What is Humid Heat?

July 4, 2024

People in India exposed to extreme levels of humid heat during monsoons increased by at least 67 crores over the period 1951-2020, research has found.

About Humid Heat:

  • Humid heat results from high temperatures and high levels of moisture in the air. 
  • This means sweat does not evaporate as easily, making it harder for the body to cool off. 
  • As a result, it can “feel” hotter than the same temperature in a dry environment.
  • This perceived temperature is known as the heat index, which describes what the temperature feels like to the body when air temperature is combined with relative humidity.
  • Humid heat tends to be more dangerous as the moisture does not evaporate as efficiently, so more heat remains in the body.
  • Effects:
    • It’s common to feel damp and sticky in hot and humid heat, and you might get covered in sweat after a short period of time outside. 
    • It can contribute to feelings of low energy and lethargy.
    • It can cause hyperthermiaoverheating as a result of your body’s inability to effectively let out heat.
    • Hyperthermia can cause:
      • Dehydration
      • Fatigue
      • Muscle cramps
      • Heat exhaustion
      • Fainting
      • Heat stroke

What is Dry Heat?

  • Dry heat occurs when there is low humidity.
  • It generally occurs in hot desert climates that receive little precipitation.
  • The absence of moisture in the air allows water to evaporate more quickly, and temperatures may seem cooler than they would in a humid environment. 
  • Dry heat can feel more tolerable initially, as sweat evaporates quickly, providing some relief.
  • On the other hand, dry heat can cause dehydration faster.
  • In dry air, not only does the sweat evaporate quickly off the skin, taking extra heat with it, but the moisture from your saliva and breath will also quickly evaporate, resulting in the unpleasant “dry mouth.”