(Image credit: Simba Sleep)
A second summer heatwave is upon us and if your bed turns into a giant foam oven at night, I recommend investing in a cooling mattress that wicks away heat fast. Simba makes some of the comfiest and coolest beds I’ve tested, and its cheapest cooling mattress, the Simba Simbatex Cool Mattress, is down to £261 (was £349) at Amazon this Prime Day. It also has a machine washable cover to get rid of summer sweat.The Simbatex Cool Mattress was launched in March and is made from four layers of certi-PUR graphite-infused Simbatex foam. This material is breathable and fast to dissipate heat. So the main consideration is the height. At 23cm (9 inches), it’s slightly shorter than the average bed-in-a-box, so I’d be wary of heavier bodies (240lbs+) receiving enough pressure relief to sleep comfortably.Otherwise, at £299 for a double the Simbatex Cool is excellent value for money among this year’s best Amazon Prime Day mattress deals. Here’s a closer look, and for further savings check out our big best Prime Day deals hub.Cooling, supportive and affordableThere are only seven double sizes left on Amazon for the Simba Simbatex Cool Mattress, and it isn’t hard to see why this budget bed-in-a-box is close to selling out on Day 1 of Prime Day 2026…In the UK, Simba makes some of the best mattresses for every type of sleeper. Every Simba mattress we’ve tested has walked away with a score of at least 4 out of 5, and I’ve been sleeping on the Simba Natural Hybrid Apex (a knock-out organic mattress, on sale from £1,109 at Simba) for two years and can’t fault it.
