I used to have to carry two injectables, insulin and another but I’m not currently taking either. My insulin wasn’t iced but the other one was. I never had a problem with either. I still carry Epi Pens and again no problem. A note from the doctor is a good backup but I never had to use it. Mine are on his script pad. The notes are simple, like “GadgetFreak is a patient of mine. He is diabetic and must carry insulin and associated materials with him” and a signature.