The National Weather Service has issued an excessive heat warning for Maricopa County from 11 a.m. today, July 21, until 8 p.m. Friday, July 22.

Temperatures could reach 116 degrees.

Other counties listed under the warning are Coconino in areas below 4,500 feet, La Paz, Mohave, Yavapai and Yuma.

Health officials advise these precautions to prevent heat exhaustion or heat stroke:

• Stay in air-conditioned buildings. Find cooling centers, hydration stations and collection/donation sites in Maricopa, Pima and Yuma counties.
• Limit outdoor activity during the hottest part of the day (mid-day).
• Check on at-risk friends, family, and neighbors at least twice a day.
• Drink water before, during and after working or exercising outside.
• Check the UV Index.