When we were in Greece in the middle of a heat wave that had even the locals complaining, one of them told us to thoroughly wet a sheet with cold water then wring it out well so that it was damp all over but not dripping wet, just before getting into bed. The theory is that it causes your body temp to drop enough so that you can get to sleep, and although it dries out and thus warms up as the night goes on, it's the initial dip in body temp which is the cue for your body to be able to drop off to sleep and once you're asleep you should be fine. It worked a treat for us and for our children, who were about 10-12 at the time.
Similarly, when one of our lads had a raging temperature, having satisfied himself that the temperature itself was the main medical problem and there were no other issues, our GP (very 'old style!) astonished me by having me take his t-shirt off him, and he than ran it under the cold tap and told me to drive my son home with the car windows open. Poor little beggar was sobbing with cold before we'd got two miles down the road, but his temperature dropped and his recovery was almost immediate thereafter.