How to Choose a Cooling Mattress Protector

Do you actually need waterproof?

This is the decision that determines how cool the protector can be. A non-waterproof cooling protector, with no membrane at all, will always sleep cooler than a waterproof one — but it gives up the warranty protection that is the main reason to own a protector.

For most people the answer is to accept a thin, breathable waterproof layer and buy the cooling back elsewhere: breathable sheets, a lighter comforter, a cooler room. For a sleeper with genuine night sweats, a phase-change waterproof protector is the right splurge.

Where cooling protectors sit in the stack

Order matters. The protector goes directly on the mattress or on top of any topper, with the fitted sheet above it. Putting a mattress pad on top of a cooling protector defeats it — the pad becomes the surface you touch, and its fibres set the temperature.

• Mattress → topper (if used) → cooling protector → fitted sheet.
• Never layer a quilted pad above a cooling protector.
• Percale or linen sheets extend the effect; sateen and microfibre undo it.
• A mattress with an active cooling system needs the thinnest membrane you can find.

Managing expectations

Cooling bedding regulates rather than refrigerates. In our own testing we hold the room at 68°F and 45% relative humidity precisely because ambient conditions dominate any fabric effect — a warm bedroom will overwhelm the best protector on the market.

If you wake soaked rather than warm, the useful upgrades are, in order: room temperature, sheets, protector, then an active cooling system such as a water-based mattress pad.