I tested the caveman cooling hack and ruined my sleep — here's why

The caveman cooling method has been causing a stir online during the recent heatwaves.

The viral trend recommends closing windows and curtains during the day to keep the hot air hot. It's often used in bedrooms to create a cooler environment for sleep, similar to the dark of a cave.

Fairly obvious, right? The caveman method is less a sleep 'hack' and more the advice your grandparents passed on.

But while decades of experience (and a fair few Tom's Guide comments) insist on the caveman method, I won't be using it this summer. And no, it's not just that the heat has gone to my head...

Why I won't be using the caveman method

The caveman method is a very sensible (and as Tom's Guide readers have pointed out, "obvious") method to keep your room cooler in a heatwave.

And I'm a pretty sensible person so I've surprised myself by turning my nose up at this not-exactly-a-hack-it's-so-obvious sleep hack.

Full disclosure: I have tried the caveman method before. While calling it 'caveman' might be a modern viral trend, shutting your windows and blinds has long been a popular method to cool down your house.

Which brings me to my first problem: it didn't make my room feel much cooler.

My room was now both dark and hot

My room is on the east of the house, so I get a great dollop of sunlight to wake me up in the morning.

This is normally a good thing — I wake up fresher when there's sunshine to help me along — but in a heatwave it means my bedroom is stifling by early morning. I leave my windows and curtains open in the night to let cold air in but that's followed by heat as soon as the sun rises.

Even if I close my curtains once my alarm goes off, the damage is done. Instead of the cool cave I'm dreaming off, it just leaves me in a warm, dark room. Which brings me to the next problem...

It sends me circadian rhythm out of sync

Against all good advice but as a necessity of space, I have to work in my bedroom.

To prevent work ruining my sleep, I have strict boundaries. I make time for breakfast every morning to define the start of the day and I go for a walk every evening to separate work from relaxation.

And the final crucial element is that I keep my room bright when I'm working, pitch black when I'm sleeping. I have a SAD lamp and an eye mask to ensure I can achieve this no matter the conditions outside.

But the caveman method plunged my workspace into 'bedtime' mode.

My SAD lamp brightened things up but within a few minutes it started pumping out its own heat. My dim overhead lamp is cooler but the low light just made me feel sleepy.

And I was also miserable. That's what a stuffy, dark room will do to you.

My circadian rhythm was all over the place, further confused by the still-bright conditions of my evening walk. I crawled into bed with my head firmly stuck in 'work' mode.

In my only slightly cooler room I tossed and turned with a racing mind. When I did fall asleep, I dreamt of mattress deals.

Should you use the caveman method?

The caveman method is undoubtedly an effective way to cool down your house, as evidenced by the fact people have been using it for eons.

However, while cooling might seem top priority when trying to sleep in a heatwave, our circadian rhythms have their own demands.

For me, that means a clear separation between my workspace and my sleep space, even though they're in the same room. This was something the caveman method worked against.

So for cooler sleep I'll be leaving the Stone Age to jump forward a few millennia and leaning on ye olde electric fan method.

3 methods for cooler sleep I'll be using instead

1. Making my own air con

A few years ago I bought a mini fan on a whim and it has since become one of my prized possessions. Despite a small size it packs a cooling punch during warm weather, especially when combined with a frozen bottle of water.

To make your own air con, all you need is a fan and some ice. Simply face the fan towards your bed, place a bowl of ice (or a bottle of frozen water) in front of the fan and turn it on. The fan will blow the cold towards you.

2. A warm shower before bed

In the morning vs evening shower debate I tend to fall on the side of 'whatever's most convenient' but during summer a warm shower can help me cool down before bed.

Moving from the warmth of the shower into a cooler bedroom causes my core temperature to drop, bringing me closer to the perfect temperature to sleep.

It also washes off the sweat, sun screen and allergens that threaten to ruin my mattress and my sleep when I go to bed in summer without an evening shower.

3. Ditch the duvet and use a top sheet

While I swap my winter bedding for lighter, airier options at some point in mid-spring, during a heatwave even my most breathable duvet is too much.

I'd kick off my covers entirely except I like the weight of even a thin blanket. So in summer, I'll switch my duvet for a top sheet. It's snuggly but not warm.