Heat intolerance is the inability to be comfortable when external temperatures rise.

Heat intolerance often produces a feeling of being overheated and can cause heavy sweating. Heat intolerance usually comes on slowly and lasts over the long-term.

• Amphetamines such as appetite suppressants
• Caffeine
• Excess thyroid hormone (thyrotoxicosis)
• Menopause

Keep room temperature at a comfortable level. Drink plenty of fluids.

Call your health care provider if you have persistent and unexplained heat intolerance.

Your health care provider will take a medical history and perform a physical examination.

Medical history questions may include:

• Time pattern
  • Have you had heat intolerance before?
  • Have you always had difficulty tolerating heat?
  • When did you begin to develop heat intolerance?
  • Do you often feel hot when other people do not complain of the heat?
• Associated complaints
  • Is it worse when you exercise?
  • What other symptoms do you have?
    • Dizziness
    • Fainting
    • Palpitations
    • Rapid pulse (heart rate)
    • Vomiting

• Blood studies
• Thyroid studies (TSH, T3, free T4)

After seeing your health care provider:

You may want to add a diagnosis related to heat intolerance to your personal medical record.

Ladenson P, Kim M. Thyroid. In: Goldman L and Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders; 2007:chap 244.