Do cooling mattresses work?

Yes, cooling mattresses work for many hot sleepers, but how well depends on construction. A mattress with coils and breathable top layers sleeps cooler than a dense all-foam bed with only a gel label.

Heat builds up where foam hugs the body and traps warmth. Cooling mattresses fight this with airflow through coil cores, open-cell or gel foam, latex, and natural-fiber covers. Gel or copper infusions are a secondary feature. They won't make a mattress feel cold, and they can't fix a design that blocks air.

Cooling mattresses rely on top layers of gel foam, latex, or natural fibers to move heat away.
Hybrid mattresses combine individually pocketed coils with 2 or more inches of foam comfort layers for better airflow.
Innerspring mattresses sleep coolest of the common types because air passes freely through the interconnected coil grid.
Gel-infused and copper-infused covers are secondary cooling features, not substitutes for airflow through the mattress.
All-foam mattresses contour deeply and are the construction type most likely to sleep hot.