The general wisdom seems to be that insulin resistance decreases in hot weather so T1 are inclined to go low. However, my husband's seems to be doing the opposite. He's not unwell and he started a new insulin pen (Novarapid) just in case, drinking loads of water, increased his basal and following sick day rules for corrections but still very high ie 20+. It comes down overnight to something sensible and then rises with the temperature during the day. His control is usually really good. Anyone else experienced this? Thanks!