One man has shared a simple DIY home cooling trick he claims can help beat the heat without air conditioning or even a fan – and it costs next to nothing to try17:25, 07 Jul 2026A man has shared a cooling method he learnt from his aunt that he says can help combat the heat without resorting to air conditioning or even a fan. And the advice comes just as Britain faces what the Met Office is calling the UK's third heatwave of the year.‌Sam Smith, 40, claims the method costs virtually nothing and could prove invaluable for those attempting to stay cool while keeping energy bills in check. The TV studio floor manager, from Peterborough, posted the tip on social media and it has already garnered more than 17,000 likes.‌The method involves nothing more than a bowl of cold water positioned on a windowsill. Sam explained he first encountered the peculiar technique years ago when his aunt would leave large bowls of water by the window each summer.‌At the time he found it rather strange, but later learnt there was genuine science underpinning it. "So you just fill a bowl with cold water or ice," Sam said."When you place the bowl on your window sill, or in front of a fan, the water evaporates into the air. This process absorbs heat, effectively lowering the ambient temperature of the room without electricity.‌"It's a great little hack and it worked for us at home. The hack could be especially useful for people on a tight budget or elderly people looking for a cheap way to stay cool during hot weather."Temperatures could reach 34-35°C later in the week, the Met Office said on Monday, July 6. Met Office Deputy Chief Forecaster Steven Keates said: “Parts of the UK are entering heatwave conditions: the third heatwave in the UK so far this year."However, unlike the May and June heatwaves, we are not expecting this heatwave to be record-breaking. Temperatures this week are not expected to reach the highs we witnessed last month, though parts of southern England in particular are likely to see several days in the low 30s Celsius, and a few places could reach 34-35°C later this week."‌'My room dropped 10 degrees in temperature'Sam reckons the simple trick could make a genuine difference for households seeking to remain comfortable without ramping up their energy consumption. The cost-effective advice has resonated with people online.One impressed viewer commented: "Wow. Really worked...dropped my room like 10 degrees." Another said: "I'll try this later. Thanks."Someone else wrote: "I tried it last night and it worked for me." A fourth person added: "Yes - I'll ditch the air con."Article continues belowNot everyone was won over, however. One doubtful social media user joked: "And I'd wake up to the god damn pigeons taking a bath in it!!"The government's gov.uk website also has useful guidance to keep homes cooler in the heat. It says that "growing plants outside can provide shade, which may be particularly helpful in front of south-facing windows, while plants inside may help cool the air."In another piece of advice linked to windows, the website also says that people should think about getting internal blinds or curtains, or external shutters - and says "roller blinds or awnings are also very effective".