Is there such a thing as too hot to work?

I work at a Sonic Drive In. This place is absolutely falling apart....The ice cream and slush machines leak all over, the hot water is hot enough to send you to the hospital if you're not careful, the roof leaks all over us every time it rains, the list goes on and on... While all of that is hard to deal with, the worst part is that the a/c is not working. I know that a/c is a luxury and is probably not required by law, but this is killing us! It was 95 degrees in there at 6pm when the outside temp. was in the upper 60's. I don't even want to think about how hot it will be when the outside temp. reaches 80, 90, or even higher! I'm sure I could tuff it out for the summer, but I'm really concerned about the two pregnant women we have there who work 40+ hours a week! Is there anything we can do, or do we have to deal with it? Yes, I know we could quit.....