I am so sorry the heat is doing this to you. It has to be very scary! I don't have this issue with heat but a few ideas came to mind.

When I lived in good old "warm" Arizona (115 degrees) I had a water bed. It was very cool and kept me cool. Sometimes so much that I had to turn the heater on to warm the water in it. The new beds don't have so much of a wave when you get in and are more stable.

In hospitals, they have special beds that cool the bodies of patients that have fevers. I think they contain water that circulates, mabe with some sort of beads? I have not worked in a hospital for years, so those of you who know more, please chime in.

Also somewhere recently, someone mentioned using a hot water bottle with cold water to feel cooler in bed. That sounds very short term.

Can you tolerate a fan blowing on you at night?

Last but not least, I know this sounds different, but I put aluminum foil, shiney side out, on the lower half of my windows that do not face the street. It really helps keep the heat out in addition to closing the drapes and blinds.

You usually are so cheery and I am so sorry you are not feeling well.