The heatwave has had us all searching for ways to keep cool, so I put scientists' surprising hot coffee theory to the test against iced coffee - and one drink came out on top13:09, 23 Jun 2026Sweltering temperatures have gripped the nation in a record-breaking June heatwave here in the UK.‌And while it's been brilliant having the chance to spend more time outside without being bundled up in countless layers, it's far less enjoyable being stuck indoors without the luxury of air conditioning that those across the pond in the US so often take for granted.‌Homes in the UK simply aren't designed to withstand scorching weather, so like everybody else, finding ways to stay cool has become something of a mission. According to scientists from the University of Ottawa's School of Human Kinetic, one surprising solution is to drink a hot coffee or tea, which apparently triggers more sweating and helps regulate your body temperature in the process.‌Coffee is the one thing that gets me out of bed each morning, yet lately I've barely been able to face it — it's simply been too hot to stomach.However, after looking into the theory that a hot brew can actually cool you down, I decided to put it to the test with both hot and iced coffee to find out once and for all which offered the greater relief.‌First up was a steaming hot flat white. Despite it being only 9.30am as I was getting it ready, my flat was already stifling — so it's fair to say I wasn't exactly looking forward to it.But in the name of journalism, I sat down and started to sip. Scientists claim that drinking something hot sends a signal to the brain, instructing the body to sweat more.This perspiration then evaporates, helping us cool down, and we supposedly shed more heat than we gain from the hot drink itself.‌Unfortunately, this wasn't quite my experience, as the hot coffee didn't exactly have me breaking into a sweat — though it certainly warmed me up, which was far from ideal given it was already pretty hot.The double shot gave me the morning kick I needed, but that was about as far as the hot coffee's appeal stretched. By the time I'd finished the cup, I was absolutely desperate for something that would actually bring my temperature down.So I threw caution to the wind, ignored the scientists' advice, and reached for an iced drink instead.‌I loaded a glass with ice, poured in an espresso shot, topped it off with some oat milk, and gave it a good stir to blend it all together.From the very first sip, the relief from the heat was far greater than anything the hot coffee had managed. It was a far more pleasurable experience all round, and I made a point of enjoying every single mouthful.Article continues belowThe sensation of holding the ice-cold glass also made a real difference — something the first option just couldn't offer. Afterwards, I genuinely felt far cooler than I had after drinking the hot coffee - despite it being slightly later in the day when temperatures indoors were even higher.I had been genuinely eager to put the hot coffee theory to the test, as I would have been impressed had it actually worked - but sadly it just wasn't for me.Residents of warmer European nations are well known for reaching for a hot coffee to help them beat the heat. But perhaps we simply aren't yet accustomed to the idea, as I'll be sticking to iced drinks for as long as the heatwave continues.