Too cold or too hot in bed - summary
- Overheating is a common sleep issue because your body quickly warms the foam layers beneath you, leading to restlessness, while a partner may feel cold at the same time.
- Sleepyhead has partnered with US tech firm KülKōte to create a temperature-regulating mattress layer aimed at helping people avoid getting too hot or too cold.
- KülKōte uses microcapsules that warm and liquefy when you lie down, absorbing heat and moving it away from the body, while adjusting so it doesn't remove too much heat.
- KülKōte activates when skin temperature reaches 29°C to 33°C and cites University of Auckland testing: in a simulation, the sleep surface reached 29°C and stayed there for 22 hours, while a traditional mattress surface reached 35°C.
- KülKōte's temperature-regulating technology helps you stay not too cold or too hot in bed.
Too cold or too hot in bed
Overheating in bed
One of the most common complaints when you're in bed is that feeling of being too hot. When you jump into bed, you're like a human water bottle, and you quickly start to heat up the foam layers below.
This results in throwing off covers, sticking out a foot to cool down, or just general unrest while trying to sleep. However, your partner might suffer the exact opposite and feel cold in bed.
We've teamed up with a US tech firm, KülKōte, to create a heat-regulating innovation that's designed to help you sleep without getting too hot or cold.
KülKōte temperature regulating technology
"The technology's been around for a while, but no one's really thought to put it in a mattress before," says Sleepyhead owner Graeme Turner. So how does it work? Inside KülKōte are tiny microcapsules which, once you're lying on the mattress, heat up and liquefy inside the layer and start the process of absorbing heat. Which might make the bed feel cooling.
"The advantage of it is that we put a coating of the KülKōte on the foam, so when you're lying on the bed there's actually a coolness to the bed and it moves the heat away from your body," says Graeme.
However, KülKōte cleverly doesn't take away all your heat. It senses what's needed to keep the bed cool or warm according to your body temperature.
How to keep cool in bed
Here's the simple science behind KülKōte in your mattress. When your skin temperature reaches between 29°C and 33°C, the KülKōte technology activates. University of Auckland testing found that in a simulation of someone asleep on the KülKōte mattress, the sleep surface reached 29°C and stayed at this temperature for 22 straight hours. Now that is a cool bed!
But, on a traditional mattress without KülKōte, the sleep surface reached 35°C and stayed that way – a full six degrees hotter. A hot mattress is not ideal to sleep in unless you're a hot sleeper.
It's similar technology to what's used in spacesuits to regulate the body temperature of an astronaut. Bringing this innovation back to Earth and into your sleep has become an integral part of the Sleepyhead product design team. Graeme Turner is adamant it will "revolutionise the way beds are made in the future".
His product design team has worked with KülKōte to advance the innovation further by integrating both silver and copper into the technology to boost its benefits. Silver has for centuries been used as an antimicrobial to kill harmful bacteria. It's now been combined with KülKōte to not only help regulate temperature but also to keep the mattress fresher and more hygienic for a healthier sleep.
"KülKōte has really been a game changer for us in the way we look at how people sleep."
How to stay cool at night in bed
Combining copper and KülKōte together supercharges the temperature regulation, as copper is one of Mother Nature's best-known thermal conductors. Sleepyhead's Group Innovation Manager Ashe Seatter says: "KülKōte has really been a game changer for us in the way we look at how people sleep.
"We see a lot of innovative opportunities for the future around bed manufacturing as we constantly try to perfect what a great night's sleep looks like," he says.
Hot and cold mattress
"Usually I sleep cold, the new mattress has a nice temperature." – Lynette, Katikati
A common question in the bed business is whether you sleep hot or cold. It's interesting to note that women as a general rule sleep colder than men. This can be put down to your metabolic rate. Women have a lower metabolic rate so they produce less heat than men and this can make them feel colder in bed.
Do cooling mattresses work?
"We replace our bed every 10 years and when I saw KülKōte, I wanted to try it as hot flushes are unfortunately a part of my life at the moment. Getting a good night's sleep makes such a difference to life!" – Sue, Otago
Men typically have more muscle mass and generate more heat, so that might explain why there may be a lot of disparity – not to mention duvet hogging – between men and women in bed. KülKōte goes some way to help through its amazing temperature regulating technology. It's now available exclusively in Sleepyhead beds. Try it and feel it yourself.
Making the right choice for you
No matter who is going to sleep with you, investing in the right sized mattress is one of the most important factors. Bed size is a key determiner of the quality of the sleep you'll have. So don't rush into picking a certain size mattress because that's what you've always had.
View our range of mattresses or take our Sleep Selector Quiz to find the right mattress for you.