How do I keep food from going bad at school since I have no access to a refrigerator or microwave?

I’m a college student. I work and commute to campus on Monday, Tuesday, Thursday, and Friday. I buy my meals for the week and pack them in takeout boxes and put them in the car. It’s been warm outside lately so I’m worried the food is going to go bad while in my car. How do I prevent this from happening? Should I purchase a microwave, a vacuum insulated bag, or something else?