Hi sorry you didn't get a response earlier, but I'm T2 & I'm on Humulin 3 Insulin with Metformin (6x500 a day) also Glicazide (1x a day) & Januvia (1x a day. I've been on insulin for 6 weeks now & have not had the warmth you're describing. Are you storing your insulin as directed? With mine unused insulin needs to be in fridge & once use needs to be at room temp away from heat or sunlight. If unsure read through your info sheet that comes with your insulin or ask your GP. Hope that helps. Rachel