Silentnight Heat Genie Self Heating Mattress Topper reviewed

The Silentnight Heat Genie Self Heating Mattress Topper is a non-electric topper that uses a heat-reflecting foil and a thermal lining to add up to 7.5 tog of warmth to a bed, priced from £36 for a single. It is a winter product: it warms by reflecting your own body heat, not by using power.

How it works

According to the Silentnight product page, the foil layer reflects body heat back to the sleeper while the thermal lining and a deeply filled quilted top hold it in. Silentnight also suggests it can help you save on heating bills; that depends entirely on how you heat your home, so treat it as a claim.

Warmth, safely

Cold bedrooms are a real problem in the UK winter, and government guidance on keeping warm and well advises heating the rooms you spend a lot of time in, including the bedroom, to at least 18°C. A topper that reflects heat is a low-cost supplement, and it avoids the plugs and cables of an electric underblanket. The flip side is that a bed that is too warm disturbs sleep: the NHS lists a room that is too hot or too cold among the causes of insomnia, so take the Heat Genie off when the weather turns mild.

Sizes and prices

Prices are Silentnight’s regular prices, checked in September 2026. Silentnight sells single, double and king; Argos also lists a super king. Silentnight gives no depth, while Argos lists it at 2cm, so do not expect it to soften your mattress much; we rate it soft, 3 out of 10. Delivery takes 2 to 3 working days, with a 2-year guarantee.

Who it suits

The Heat Genie suits people who feel the cold, rooms that are hard to heat and people who keep the heating low at night. It is not a comfort topper, so pair it with one if your mattress also feels too firm. In spring, take it off rather than leaving it on the bed all year.

Tog is the thermal insulation rating used for duvets, so the “up to 7.5 tog” figure describes the added warmth in the same units you use when choosing a duvet. It is a single-layer product with no controls, so the only way to adjust the warmth is to take it off.