Heat waves

The National Weather Service developed the heat index to help people identify days when the risk for a heat illness is higher than normal. During a heat wave, the heat index is excessive for many days in a row. Everyone has an increased risk for a heat-related illness during a summer heat wave.

People who have an increased risk of developing heat-related illness during a heat wave include:

  • Older adults, who may not notice excessive heat, do not sweat as effectively, or do not feel thirsty.
  • Small children, who can't transfer heat very well.
  • People with chronic medical conditions.
  • People taking medications, such as heart medications or tranquilizers, for serious psychiatric disorders or depression.
  • People with weight problems.
  • People with alcohol or drug use problems.
  • People with mental health or developmental problems.

Other factors that affect a person's risk for a heat-related illness during a heat wave include:

  • Living in cities, because heat is trapped by tall buildings and air pollutants.
  • Living alone.
  • Not having cooling devices, such as fans or air-conditioning.


Author: Jan Nissl, RN, BSLast Updated: December 12, 2006
Medical Review: Martin Gabica, MD - Family Medicine
H. Michael O'Connor, MD - Emergency Medicine

© 1995-2008 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

Click here to learn about Healthwise