i keep all my insulin in the fridge after getting it, but i carry 2 vials with me in my purse. one is open i m using and the other in case i need it. i have not had problems but they are not there more than 28 days. I carry insulin with me mostly when my daughter and I workout at the fitness center, we are both diabetic and use the same insulin and we both use pumps. again we have no problems with novalog, we did have problems with humalog due to novalog having a better tolerance to heat.
