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.

Sensitivity to heat; Intolerance to heat

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

Updated by: Elizabeth H. Holt, MD, PhD, Assistant Professor of Medicine, Section of Endocrinology and Metabolism, Yale University. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.