PRO TIP: Injecting insulin that is at room temperature can make injections less painful compared to colder insulin directly from the refrigerator (so allow it to sit out for some time before using a new insulin pen/vial).

It's important to keep insulin away from extreme temperatures (like in a car or next to a window) and not to freeze it, as freezing can damage the insulin and make it ineffective. Never heat insulin either. (like in a microwave!)