A'ndrea Elyse Messer Science & Research Information Officer Penn State Public Information 312 Old Mail University Park, Pa 16802 814-865-7517 office 814-867-1774 home BXM7@psuvm.psu.edu Internet 76520,3240 Compuserve 8-2-93 WHEN YOU'RE HOT, THE MONITOR LETS YOU KNOW University Park, Pa. -- Researchers at Penn State and Westinghouse Electric Corporation have developed a portable monitor to tell firefighters, foundry workers and others who work in intense heat when their bodies have had enough. The personal heat stress monitor, designed to be worn on the worker's body, is the first such monitor to be commercially available. The cleanup crew at Three Mile Island nuclear power plant endured temperatures as high as 155 degrees Fahrenheit after the well-known 1979 accident. Other nuclear plant workers regularly work in similar, though less extreme, conditions -- temperatures of 130 are not uncommon in some areas of nuclear power plants. Soldiers in desert operations and even race car drivers also endure high heat in their work. Many such jobs also require protective clothing -- for example, nuclear plant employees typically guard against radiation by wearing coveralls, a protective suit of impermeable plastic, rubber gloves taped at the wrists and ankles, and a face mask. "It's like putting yourself in a Ziploc bag and running around on a hot summer day," says Dr. Larry Kenney, associate professor of applied physiology in the College of Health and Human Development and one of the inventors of the monitor, which has been patented. At Noll Laboratory for Human Performance Research, Kenney has spent more than a dozen years investigating the effects of heat stress. He has worked to identify people whose bodies may have trouble tolerating a hot environment (for example, those who are overweight or have high blood pressure), and he has helped evaluate the effectiveness of "personal cooling garments" -- work clothes that incorporate ice. More recently, working with colleagues at Noll and Westinghouse, and with funding from the electric power industry, Kenney helped design a heat-stress monitor that workers can wear on the job. The monitor is sold by Metrosonics, a Rochester, N.Y., firm. The monitor has two parts: a sensor/belt assembly, worn around the chest under the worker's clothing, and a monitor module (a device about the size of a Walkman), worn in a breast pocket. The belt has electrodes to measure heart rate and a copper disk system to monitor body temperature; this information is transferred to the module, which continually monitors the worker's risk. Three different lights -- green, yellow and red -- and several tones tell the worker how much safe working time is left. "We tell workers to listen to their own bodies, and this just gives them an additional tool," explains Kenney, who helps provide training programs for industry on reducing the danger in hot jobs. "If you've been working for 40 minutes and you still feel fairly good, but the device tells you that heat stress is impending, maybe you should begin leaving the area. "For most people, signs of heat strain come on gradually as a dull headache and light-headedness. Next you may notice that your skin is clammy and the hairs stand on end. The device is intended to get workers out of the heat -- and potential danger to themselves and others -- before they get to that point." The module also stores a record of the worker's changing body temperature and heart rate, and can print out the information when the shift is over. The record shows the employee how his or her body reacted while working and helps management to identify jobs that are particularly risky and need to be redesigned. Researchers at Penn State and Westinghouse spent two years developing the monitor. "Westinghouse built a prototype based on our input, and we brought it back here to test it," Kenney says. After testing the device at Penn State on a variety of subjects who were wearing various kinds of clothing in a number of different situations, Kenney field-tested the monitor in two nuclear power stations, where workers were evaluated while performing their regular duties. Few, if any, deaths among workers in the electric power industry have been attributable to heat stroke, Kenney says. But heat stress can be a contributing factor in many falls and other on-the-job accidents. The personal heat stress monitor is designed to reduce the number of such accidents. In addition, the monitor could increase a power plant's productivity by allowing workers to venture into the hottest areas and perhaps stay longer than they otherwise would, because their safety can be closely monitored. "Nuclear power plants run on cycles," Kenney explains. "They'll be running for four months and then have a scheduled shutdown for two weeks to do routine maintenance. When they shut down, the question is whether to wait a week for the temperature to drop from 130 to 90. If they do, they've lost a week of productivity. "The personal monitor helps make it possible to go in and do some work while the room is still hot." Kenney continues to research ways of protecting the body from excess heat. In a project supported by W. L. Gore and Associates (makers of GORE-TEX), he is developing and testing protective clothing that the Marine Corps could use in chemical warfare in hot climates. Because the new fabrics have chemical protection sewn in, they could replace the bulky extra layers that were used during the Persian Gulf war. **tmh/ps**