In proper cooling mattress territory, you'll find models with technical fabrics in their upper covers, and foams geared specifically towards dissipating heat. That's known as passive cooling, and almost all the models in our best cooling mattress guide use this approach.
For ultimate chilling power, however, there are a handful of products on the market that offer active cooling. One is the Eight Sleep Cover, which contains water channels that can be heated or chilled to the exact temperature you prefer.