You can buy a memory foam mattress to put on top of your existing one.
Ours is about 2" thick.
We have a deep m/phone mattress and you do have to turn them,we are at this moment in time unable to turn the old one as it`s so heavy. so one to put on top of is ideal and easy to turn.
Also they are very warm.
Our Welfare State. Is it broken?
My four year old grandson "doesn't want me"