Cocoon by Sealy Chill Hybrid Mattress: twin was $399 now $156 at Walmart
The Cocoon by Sealy Chill Hybrid uses a variety of methods to prevent heat build-up including Phase Change Material in the cover. This pulls heat away from the body, holds it and releases it once you've cooled, so you don't overheat while sleeping. Cooling aside, the Cocoon Hybrid also promises contouring support; we found the memory foam version had a medium-firm feel, so we predict something similar here. The Walmart clearance sale is huge, reducing a twin to just $156 (in comparison, you'd be paying $539 direct from Sealy) and it comes with a 10-year warranty but no sleep trial. If you want a top-rated hybrid mattress for less this is the deal to shop.

User score: ★★★★½ (500+ reviews)

Cocoon by Sealy Chill Memory Foam Mattress: twin was $619 now $399 at Cocoon by Sealy
Even the best memory foam mattresses have a tendency to trap heat in the dense materials but the all-foam Sealy Chill impressed our testers with its breathable feel and supportive build. Like its hybrid alternative, the all-foam Chill uses PCM to absorb heat, while the firm feel prevents the stuffy 'hug' of softer foams. Our testing panel described it as "one of the most consistently cool mattresses we've slept on" in our Cocoon by Sealy Chill mattress review. The memory foam model isn't currently available on Walmart but in the Sealy sale a queen is $699 (was $1,079) which is the deal we see all the time but you do also get a free bedding bundle, 100-night trial and lifetime warranty... plus six sizes to choose from.

Our review: ★★★★
User score: ★★★★½ (8.600+ reviews)