“With overheating, it’s a simple heat balance problem,” Dr Roberts explains. The last thing you want to do is bring in hot air. But it’s exactly what we need to do – ideally paired with an open upstairs window to create a ‘stack effect’ where cool air flows in and warm air rises out. “Heat can cause short-term issues like dehydration or heatstroke, but also long-term health problems,” warns Dr Roberts. : https://www.youtube.com/watch?v=utXEby2-jac The worst thing you can do to your home on a hot day (are you guilty of this?