New heat index is established

Tuesday, July 2, 2002 | 9:48 a.m.

The American Red Cross of Southern Nevada and the National Weather Service have teamed up to publicize a more accurate heat measurement index, one that can warn people of upcoming heat waves a week before they start.

The National Oceanic and Atmospheric Administration released the improved mean heat index in May for weather forecasters to use as a tool for increasing awareness of heat waves and issuing precautions for this summer.

The mean heat index measures how hot the temperature actually feels to a person over the entire course of a day. The index takes into account ambient and surface heat, residual heat during the night and other environmental factors such as pavement instead of just a glance at an outdoor thermometer.

In Southern Nevada, where summer's daytime temperatures can reach 120 degrees Fahrenheit and stay warm all night, the local Red Cross wants all residents to be aware of heat risks.

"Heat waves often turn fatal when the nighttime temperature doesn't drop very much from a high daytime temperature," Jim Hoke, director of NOAA's Hydrometeorological Prediction Center, said.

About 175 Americans die each year from heat stress. During the 1980 heat wave, more than 1,250 people died in the Northeast and Midwest.

For more information on the mean heat index, check online (www.hpc.ncep.noaa.gov) or for heat-related precautions, call the Red Cross of Southern Nevada at (702) 791-3311.