July 15, 2007: Wartime conditions often cause changes in uniforms, and how they are used. For example, the U.S. Air Force has been sending most of its troops overseas in the last six year, usually for four month tours in hot climates. The troops don't take any civilian clothes with them, and because of that, and the heat, often wear their PT (Physical Training) uniforms (shorts and T-Shirt) when off duty. This means the PT gear wears out faster, so now enlisted air force troops will be issued four PT uniforms, instead of three. In addition, the design of the shorts will be changed, to make them appear less baggy and uncomfortable. Few troops want to hang out in uncomfortable gym shorts.

PT (Physical Training) uniforms are a post-Vietnam development. Before that, troops did their required calisthenics and running wearing combat uniforms, less the shirt (ie, just the T-shirt). There was a lot of resistance, from old timers, to letting the troops do their PT in shorts and sneakers. The argument was that, in combat, they would be wearing the heavier combat boots, and long pants. But the rationale was that short pants reduced heat injuries, and running in boots for long periods caused foot and ankle injuries that could be avoided by using proper athletic footwear. In combat, you do not do 5-10 kilometer runs in combat boots. The decision to switch was popular with the troops, and it did reduce injuries. There was no discernable decline in ability to move fast while in uniform. Moreover, the troops liked to use the PT uniform for leisure wear. Each service has a different PT ensemble, but all usually include cold weather stuff as well (sweat pants and sweat shirts).