[3] The ACS is a stand-alone shirt designed specifically for use with Improved Outer Tactical Vest (IOTV) in warm and hot weather instead of the blouse, and was introduced in 2007.

The ACS, in conjunction with the Fire Resistant ACU (FRACU) trousers, provides neck-to-ankle protection against burns.

Traditionally, flame-resistant uniforms have been reserved for military personnel such as aviators, fuel handlers and combat vehicle crew who were most likely to encounter fuel-related fires.

In January 2007, the Army began shipping 160,000 flame-resistant Nomex uniforms - The Flame Resistant ACU - for soldiers assigned to at-risk convoy operations.

The shirt’s torso is constructed of two highly breathable flame-resistant fabrics with advanced moisture management capabilities.