K-State testing personal cooling systems on Fort Riley soldiers
Tuesday, November 28, 2006
MANHATTAN -- Of all the things soldiers have to think about while serving in Iraq and elsewhere in the Middle East, weighing safety versus comfort shouldn't be one of them.
That's why researchers at Kansas State University and are studying the kinds of personal cooling systems soldiers use. In the part of the project now under way, Elizabeth McCullough, professor of apparel and textiles and co-director of K-State's Institute for Environmental Research, is working with soldiers from Fort Riley to find the personal cooling system that best meets soldiers' needs.
In Iraq, temperatures can average 108 degrees Fahrenheit during June and July. Our bodies naturally cool themselves by releasing sweat. But when soldiers wear body armor that covers their torsos and sometimes upper arms, the heat there gets trapped, making them not only uncomfortable but also at greater risk for heat stroke and other health problems. Personal cooling systems can make soldiers more comfortable and reduce the risk of heat-related injury.
McCullough said personal cooling systems usually are one of two varieties. Some cool the body by circulating air between the body armor and the skin surface sing a system of fans. Others circulate a cooled substance like water or air through tubes next to the body. But both of these methods have their drawbacks, McCullough said. Whereas personal cooling systems that use fans must be connected to a power source, those that use a phase change material like ice or paraffins lose their ability to cool when the soldiers' bodies warm the substances up again.
Also, since soldiers require mobility for their own safety, they can't stay connected to a power source or replace phase change materials easily while in the field.
McCullough said weight is another important factor for soldiers, whose body armor can weigh 40 pounds and whose gear can add even more weight onto that.
"All of these personal cooling systems add bulk and weight and they may decrease the soldier's mobility," she said. "The soldiers are having to ask if the extra cooling is worth it."
For the experiments, male soldiers were recruited from the 4th Brigade, 1st Infantry Division at Fort Riley to test personal cooling systems. The soldiers test the equipment in a special chamber at the Institute for Environmental Research.
"The conditions in Iraq are very hot, but they're also dry, and we're simulating that in the chamber," McCullough said.
The 104-degree Fahrenheit chamber has equipment like large fans that recreate wind speeds and a bank of lights simulating the radiant heat from the sun. Whereas people in many climates lament the effect humidity has on how hot it feels, McCullough said a greater concern in the desert is the radiant heat coming off the sun.
"That creates a tremendous amount of heat," she said.
In the chamber, the soldiers wear body armor and personal cooling systems and walk on treadmills while researchers record data like the soldiers' rate of oxygen consumption and their body temperatures. Researchers also ask the soldiers about their preferences among the equipment types.
The personal cooling systems being tested at K-State include both those developed in the private sector and those developed by NASA. So far, McCullough has tested six varieties of personal cooling systems and hopes to test even more in the future.
"It would be ideal to see if there's a cooling system that can help the soldiers perform better and longer in extreme heat," she said.