Soldiers walk on a treadmill in the tropical chamber.
Courtesy of the U.S. Army
Each year, some 20 soldiers experience Afghanistan's 118°F heat for the first time not in the field but in a lab in Natick, Massachusetts. For six decades, the Doriot Climatic Chambers has created everything from deserts to blizzards to test equipment before real-world deployment-and it's the U.S.'s only military lab that uses human volunteers to do it.
The chambers are divided into two areas: tropic and arctic. Josh Bulotsky, the electrical engineer who manages the lab, can control every aspect of each climate. Two 500-horsepower cooling systems and a heater create -70°F to 165°F temperatures; dehumidifiers and water misters produce 10 to 90 percent humidity; sprinkler heads simulate rain; and a snow machine makes winter storms. In the chambers, soldiers sometimes walk on treadmills that fit five people (to simulate a group march). And to track their health, they can swallow telemetry pills that relay their core temperatures to lab technicians. In January, the lab added the sun: eighteen 1,500-watt metal-halide vapor lamps so bright that it's impossible to look straight at them-perfect for testing portable solar panels. Brutal as the tests are, better that the troops and their equipment fail now than on the other side of the world.