Heat index


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Heat index


The heat index provides information about how hot it feels outside in the shade. It is a measure of the air temperature in relation to the relative humidity for a particular day.

The National Weather Service lists a heat index each day in the newspaper to alert people of the risk for a heat-related illness. Direct exposure to the sun can increase the risk for a heat-related illness on days when the heat index is high.

A heat index of:

  • to can cause fatigue.
  • to can cause heat cramps or heat exhaustion.
  • to is likely to cause heat cramps or heat exhaustion, and heatstroke is possible.
  • or higher is likely to cause heatstroke.

Prevention measures during days of high heat index will help reduce the risk of a heat-related illness. When the outdoor humidity is greater than 75%, losing body heat by sweating is not as effective, so other measures to keep cool are needed.

Credits


Author Jeannette Curtis
Author Caroline Rea, RN, BS, MS
Editor Kathleen M. Ariss, MS
Editor Susan Van Houten, RN, BSN, MBA
Associate Editor Tracy Landauer
Associate Editor Pat Truman, MATC
Primary Medical Reviewer Patrice Burgess, MD - Family Medicine
Primary Medical Reviewer Adam Husney, MD - Family Medicine
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Last Updated May 25, 2007

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Last updated: May 25, 2007
Author: Caroline Rea, RN, BS, MS
Reviewed By: Kathleen Romito, MD - Family Medicine
Editors: Susan Van Houten, RN, BSN, MBA, Pat Truman, MATC

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