Hi jermy4,
The following post has some information about factors that can affect sleeping temperature:
https://forum.mattressunderground.com/t/do-latex-mattresses-sleep-hot
This post has some more specific info about memory foam and sleeping hot
https://forum.mattressunderground.com/t/looking-for-a-good-less-hot-memory-foam-mattress
In short, there’s no universal advice for people who sleep hot.
In terms of what is most supportive, this is where your testing for PPP will indicate what is best for you. Any of the mattress materials can be made very supportive, but which one is most suitable for you is something only you will be able to tell.
The tutorial covers what to do if you’re going to consider online purchases where you cannot test the mattress in person. The advice is give the company a call and seek the advice of their people. They are most familiar with their product and the best to be able to listen to your needs and translate that into the best mattress from their selection. That said, it’s very helpful if you’ve followed the earlier steps at mattress retailers you can try to get a sense of what you’re looking for.
There’s no 1 size fits all advice.