This extreme heat here in the Midwest is melting me. I feel sluggish, tired, and generally not good. I know diabetes doesn't help the situation in my case. I've found an article from the LA Times that I think you'll find informative.
Those with diabetes also have sharply higher rates of heat illness and death during heat waves than the general population, in part because they may have nerve fibers that don't signal the blood vessels to dilate. This could decrease the amount of blood brought to the skin's surface to dissipate heat, according to the review. Some evidence also shows people with diabetes may have a reduced ability to sweat.
If you are diabetic you know exactly what a boil is and where you get them. Right? Here's a clip of a great article about diabetes and boils that will tell you what causes them and things you can do to prevent them.