I like u/deepmusicandthoughts idea of a thicker topper. It almost describes the activedough I mentioned, which has 2 layers to it, pressure relief and cooling comfort. You would want to consider a mattress topper cooling material encasement cover. This is what I have used (https://www.amazon.com/subrtex-Removable-Protectors-Adjustable-Anti-Slipping/dp/B082MHKSP2/ref=sr_1_3?crid=N0Q5PF0ZMNOI&keywords=subrtex%2Btopper%2Bcover&qid=1683141212&sprefix=subrtex%2Btopper%2Bcover%2Caps%2C93&sr=8-3&th=1)

Tempurpedics tempur adapt with cooling states you will sleep cool with their blend. I have their pillows, and it is really the cover that use the cooling technology, although the dual breeze pillow uses both the cover and gel layers in the pillow.

So, perhaps, whatever topper you decide, put the $ on one that say it meets your needs along with the cooling topper encasement (even though you are covering it with your sheets etc. )