Definition

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

Considerations

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.

Common Causes

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

Home Care

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

Call your health care provider if

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

What to expect at your health care provider's office

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

Tests that may be performed include:

• 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.

References

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