Ways to combat the heat?

Hello! My bf 26M (he does not use Reddit) works in a manufacturing facility that gets extremely hot during the summer. He is also constantly around burning foam fumes and hot wires that make the area hotter.

The heat is destroying him, throwing up, close to passing out, dehydration even after drinking 6-9water bottles a day + Gatorade’s.

Anyone who works in the heat regularly, what are some things you do to help yourself not get overheated in the work day? I’ll take any suggestion even the crazy sounding ones.