|"Kawasaki Electric Fan," 2004. Credit: CC BY-SA 3.0|
Part of your body's circadian system relies on your body's careful regulation of its temperature. A general reduction in core temperature helps to facilitate sleep. You achieve your lowest core temperature about four hours into your sleep period and this low point helps reset your rhythms for the day.
By no means does this suggest you make your efforts at body temperature reduction extreme, as being too cold can also keep you from sleeping. But generally speaking, the human body has a thermal pattern that includes a cooling off period at night which helps make you sleepy.
So there's a heat wave on where you live. What then? If the ambient room temperature in your sleeping space is uncomfortably high, you will end up sweating, tossing and turning because your body isn't going to achieve the lower core temperature required to become drowsy.
While there isn't a perfect room temperature conducive to sleeping for all human beings, being in a sleeping space that's 54-75 degrees Fahrenheit is one's best bet. Therefore, if you don't have air conditioning or even a fan to help move air and make you feel cooler, and it's very warm in your sleeping area, you may need to cool your core temperature with cold fluids at bedtime or even take a sponge bath using cool (not icy) water to help cool yourself off before going to bed.
Research has shown that insomniacs generally have a higher core body temperature, no matter what time of year, which could be part of their sleeping challenge. One way to help drive that drop in core temperature for them might be to take a hot bath right before bed. I know, it seems counterintuitive! But once out of the hot bath, the body naturally cools in a cooler space and this could lead to the drowsiness that can elude some insomniacs.
Also, if you wear too many blankets at any time of year and sweat a lot during the night because of it, this could hamper your efforts to more quickly fall asleep, so you might think about turning down your room temperature if you can't get rid of the blankets, or try for lighter blankets so you can better facilitate your own good sleep.