March 12, 2002
Question from Laredo, Texas, USA:
Does temperature affect the sugar level?
Environmental temperatures usually do not have a direct effect on blood glucose levels except when they also change what activity occurs, food intake etc. Temperature of insulin injection sites may have some effect on insulin absorption characteristics with heated areas (i.e., a sauna or hot tub) likely to increase absorption because circulation is increased to that area while colder areas would have some slowed absorption. Fever would tend to increase circulation and therefore increase insulin absorption, but be counterbalanced by the stress of the illness itself and the adrenalin-like surges that would raise sugars.
So, it’s all very complicated to answer in such a general question. Extreme temperatures (both hot and cold) may denature the insulin protein itself and thus decrease insulin availability if the vials are not appropriately handled.
[Editor’s comment: In addition, extremes of temperature will affect the performance of blood glucose meters.