How safe is it to sleep in your car at Mac?

Title. A friend of mine commutes from a long ways away (she couldn’t afford residence) and owns a large enough vehicle to comfortably sleep / sorta live in (adjacent to a mini van). She parks on campus but was telling me recently that she’s considering sleeping in her car on the nights when she has classes until 10 or goes out for drinks with her friends in Hamilton and can’t spend the night in the dorms.

Is this even allowed? Will you be fined if you’re caught sleeping in your car and more importantly is it safe??