Its always a good idea not to use a waterproof mattress protector as these definitely warm up a memory foam mattress even more! if you suffer from being hot whilst sleeping look for a memory foam mattress with a coolmax cover this will considerably cool the sleeping surface.Also its a good idea to do a bit of research regarding memory foam mattresses in general.A solid foam/memory foam will feel completely different to a sprung memory foam mattress.If you have never slept on a solid foam mattress go for the sprung memory foam it will feel more like a regular mattress.