Heat Rash: Symptoms & Signs

Medically Reviewed on 10/23/2020

Heat rash is a skin condition that occurs in hot, humid conditions and typically resolves when the temperature becomes cooler. Heat rash is also known as prickly heat.

Signs and symptoms of a heat rash include

Other associated signs and symptoms can include a

  • prickly or tingling feeling and
  • skin flushing or redness.

The rash tends to develop in skin folds or in areas where clothing is tight and restrictive.

Cause of heat rash

Blockage of the skin's sweat glands causes a heat rash, leading to an inability of sweat to evaporate. This causes inflammation that results in a skin rash.

Other heat rash symptoms and signs

  • Itching
  • Pink or Red Skin Bumps
  • Prickly or Tingling Feeling
  • Skin Flushing or Redness
  • Small Blisters


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Jameson, J. Larry, et al. Harrison's Principles of Internal Medicine, 20th Ed. New York: McGraw-Hill Education, 2018.