I am very curious to know what would happen if I was to store medicines in temperatures greater than what is directed for the drug.

I have a prescription for Nicotine Gum (Polacrilex), and it directs you to store at temperatures around 68-77 Fahrenheit. Well, I want to keep a box at my house, in my car, and at my work. The problem is, if I keep a box of the gum in my car, the temperatures can easily exceed the directed storing temperatures on the box.

What are the side effects of taking this after it's been heated, cooled, heated, cooled, repeat the process, and finally consumed? What could go wrong? I've had a stick of gum that's been left in my car all summer long, and it tasted fine. And a side note, I am also curious to know generally, what could go wrong for any medicine that was stored in temperatures not ideal for the type of medicine it is. I would also like a general idea of what medicines are O.K. to store at higher temperatures (if applicable), and ones that must follow strict temperature guidelines.