Hi there -- Thanks for your question. I am generally pretty skeptical and reserved when it comes to the many "cooling" claims one hears in the mattress industry these days. That said, in the case of this mattress, I do have to say that the quantity of phase change material used in the top of this mattress is indeed very effective. As a result of this, the mattress has a palpable coolness to the touch that you notice instantly. Of course this dissipates as you sleep on it, but overall I think this mattress is well above average in terms of its cooling properties.

FYI, we'll be releasing our full in-depth review of this mattress in the coming weeks.