Synthetic athletic clothing containing polyester and nylon has been prohibited for Marines conducting missions away from forward operating bases and camps in Iraq.

The ban on popular clothing from brands such as Under Armour, CoolMax and Nike comes in the wake of concerns that a substantial burn risk is associated with wearing clothing made with these synthetic materials.
The problem with the synthetic material is that, if exposed to extreme heat and flames, the polyester based material may melt and fuse to the skin.