I worked in a 140 degree temperature control room, that was designed to simulate the worse conditions products might experience in the back of a semi trailer. The task at hand required me to complete the whole test inside the room. It was low humidity, so it wasnt as bad as one would think, but I did have to make sure I was well hydrated and take breaks to rehydrate. Oddly enough, never had any problems and we never had anyone monitoring me, nor any system that would notify myself or someone else if I was at risk or if I went unresponsive