I work at a warehouse, and it gets loving hot in the back where all of the boxes and shelves are. It's a big warehouse, so it is pretty hard to cool. There is a swamp cooler, but it only really helps if you are standing directly in front of it. The air conditioner in the front office is broken, so whoever is working there takes the full force of the heat, because the swamp cooler can't reach.
It gets especially hot when you have to climb the ladder to the top of the shelves and move heavy boxes down. It doesn't help that all of the boxes have heavy winter gear in them.