What happened to HBT coveralls?

[Fistula]

In many training films from the 1940s troops can be seen running obstical courses in HBT coveralls. When I was an armor crewman I rather liked coveralls. When I where mechanics coveralls, all of the guys ask me how they can get a set. Why didn't the Army stay with coveralls? They seem like a good utilitarian uniform.

Even now, when I go to the range I where coveralls. I can just slip them on over shorts and a t-shirt and roll around in the dirt all day.

[nartron]

Coveralls are still issued to specific groups of troops, just not necessarily called coveralls anymore (e.g. flight suits, etc.) As you mentioned coveralls are still issued to armor crews. Most of the coveralls are made from Nomex now for fire resistance purposes.

For infantry or other active ground combat units coveralls were found to be impractical due to the need to relieve oneself under fire, necessitating disrobing almost entirely. Another concern was the fact that the HBTs in particular were used in hot weather and coveralls tend to trap more heat than a two piece uniform that can be vented more effectively.

From strictly a supply standpoint it is more cost effective to be able to replace a shirt or trousers as worn out vs. a complete suit. Of course cost effectiveness hasn't been a hallmark for the military or government in general.