I swear by this sleep hack for hot summer nights — and science backs me up

Summer brings many difficulties when it comes to sleep. Naturally, we sleep better at cooler temperatures. When it gets hotter outside, our bodies struggle to lower our temperature enough to fall asleep.

This, combined with general discomfort from feeling too hot and long hours of daylight wreaking havoc on our body clock, results in nights tossing and turning.

As the Sleep Features Editor for Tom’s Guide, I come across new hacks for getting better sleep every day. And I’ve tried a lot of them, from mouth taping to cognitive shuffling, but I think I’ve found the key to sleeping cool night after night.

My go-to sleep hack for summer

An easy method that doesn’t rely on fancy tech or trending hacks is taking a lukewarm bath before bed. Yep, that’s it. But don’t underestimate this seemingly simple trick. It’s surprisingly effective.

As part of my nighttime routine, I often take a warm bath before bed. Not only does this offer a period of time free from screens, it also creates a calm and peaceful environment for the mind.

I usually add essential oils like Lavender to the water and the heat helps the body physically relax, as well as the mind.

On top of this, moving from a warm bathroom to a cooler bedroom helps the body’s core temperature drop, which aids sleep.

But when temperatures are soaring, there’s no way I’m sweltering away in the tub before bed.

I couldn’t imagine anything worse. I considered an alternative cold shower, but that would have shocked my body too much to relax before falling asleep.

So, the solution? My normal bathing routine, but with the hot tap turned down. I tend to opt for a temperature that’s just edging over to ‘warm’ instead of ‘cool’. It's effective every time. But why? I asked an expert.

Why a lukewarm bath is effective for sleeping in the heat

“A lukewarm bath actually helps cool the body more effectively than a cold one,” says Dr. Jamey Maniscalco, a neuroscientist, wellness consultant, and founder of Manifest Wellness.

“When you soak in water that’s slightly below body temperature, it promotes heat loss through your skin,” he explains.

“The mild heat exposure of the bath causes blood vessels near the surface of the skin to dilate (expand), bringing more blood closer to the surface of the skin and allowing for heat to move out through the skin.”

The result? It “encourages your core temperature to drop once you get out of the bath, and that temperature drop is what helps cue the brain that it’s time for sleep,” the doctor says.

Aside from dropping your body temperature to the best range for sleep, it’s important to create and stick to a nighttime routine during the summer.

When it’s already difficult to wind down and sleep during the heat, maintaining regular habits tells your mind and body that it’s time to rest. After all, humans are creatures of habit.

By maintaining my usual routine, it’s a clear indicator to my body that it’s the end of the day and it’s time for bed. And I don’t know about you, but the feeling of uncomfortable clothes on my body when I’m hot makes me feel infuriated.

The only time I feel truly comfortable is lying in a bath with no itchy seams or non-breathable fabric covering me.

3 other ways I sleep cool at night

1. I use bamboo bedding and pyjamas

Swapping my usual cotton bed sheets for bamboo was the best decision I’ve made. This natural fiber wicks moisture away and is super breathable.

It also has a silky soft feel which remains cool against my skin. This has meant I’ve been able to continue sleeping with a duvet (key for me to feel cozy and comfortable enough to sleep) without overheating.

Opting for bamboo pyjamas means I can enjoy these benefits even when it’s too hot for any kind of duvet on the bed. Consider a bamboo mattress topper, too to add some freshness to your bed.

2. I sleep with a wool duvet

It might sound counterintuitive, but wool is a fantastic material in the heat. The crimped fibers allows plenty of airflow through them, meaning wool products are unlikely to trap heat.

It also has the ability to absorb a lot of moisture, which means it can wick sweat away from your body at night.

However, the versatility of wool means that as you’re falling asleep, you can stay comfortable and cool, but if it becomes colder at night, you’ll stay nicely warm. My thin wool duvet is perfect for this, preventing me from waking up at night.

3. I sleep on a wool and latex mattress

Certain mattress materials can trap a lot of heat. Even the best memory foam mattresses have the potential to warm up in the summer because the dense foams can stop air from flowing through it.

Instead, I opted for an organic, natural mattress made from latex, wool and cotton. All three materials are breathable and the wool pillow-top wicks moisture, keeping it fresh for longer.

The result is a constantly-cool bed that doesn’t feel sweaty even on the hottest of nights. If you're due a bed upgrade, check out the best organic mattresses to feel the same fresh comfort.