Also known as Sealy Mirrorform, visco polymer foam developed by NASA,
Memflex mattresses.

If you are using one of these new foam mattresses please can you tell
me whether it can be hotter to sleep on than a conventional spring
mattress. I am considering buying one but am worried as to what it
might be like in summer. Also is anyone aware if all makes are the
same or some are better than others?

Nigel (UK)