Why solid memory foam traps heat — and how open spring layers breathe

Restore guides · Comfort estimates are for guidance and do not constitute medical advice.

Hot sleepers often describe the same problem: they fall asleep comfortable, then wake up warm, turn the pillow over, and find the other side warm within minutes. That is not just about room temperature. It is about how heat moves — or does not move — through the material inside the pillow.

Solid memory foam is dense. Its structure is a continuous block with very small, closed or semi-closed cells. When you lie on it, your head compresses the foam and closes off even more of those small air paths. Heat from your head and body has few routes out, so it stays trapped near the surface. Flipping the pillow helps briefly, because the underside is cooler, but once that side warms up, the same dense block traps heat again.

Open spring layers work differently by design. A pocketed spring core is mostly open space: springs in individual pockets, with air channels between and around them. Air can move through those channels when you shift position, instead of being blocked by a solid block. That movement does not cool the pillow on its own — no pillow is an air conditioner — but it gives heat a way out that a dense block does not offer.

The cover matters too, because it is the layer your skin actually touches. Restore uses a Tencel cover, which is made from wood-derived fibres and is commonly chosen for sleep products because it feels smooth and breathable. Combined with an open spring core, the cover is part of a system designed to let air move, rather than a single cooling feature doing all the work.

Gel layers add another option. In Restore, gel is one of the layers you can include or leave out when you build your pillow. Some hot sleepers prefer a build with gel, others prefer a build without it. There is no single right answer here, and no temperature reduction is promised — the point is that you can try a build, sleep on it for 5 to 7 nights, and restack it if it still feels warm or too high or too low.

If you sleep hot, a few practical checks help more than any single material claim. First, check height: a pillow that is too high or too low can make you restless, and restlessness makes you feel warmer. Second, check airflow: can air move through the pillow, or is it a solid block? Third, check the cover: is it smooth and breathable, and can it be washed? Restore's cover is machine-washable cold on a gentle cycle and line-dried, while the foam and springs are spot-clean only.

For hot sleepers in Singapore, where nights are warm and humid for much of the year, those three checks — height, airflow, and a washable breathable cover — are a more useful way to choose than chasing a cooling label. A pillow designed with open spring channels and a Tencel cover gives heat somewhere to go. Whether that is enough for you is something you can only judge after a few nights on a build that is the right height for you.

Comfort estimates are for guidance and do not constitute medical advice.

Find your height — 2 minutes

Launch S$139 S$159 · Free shipping in Singapore · Warm Cream only at launch. Pre-order — first batch ships in December 2026. After you order, our customer service team will contact you within 1 working day to confirm your delivery date.

About Restore: Restore is a Singapore pre-order business. Its customizable pocketed spring pillow is built to your height with the Fit Finder, using spring, gel, and fibre layers, with a Tencel cover in Warm Cream.