It’s safe to say summer has officially started. Temperatures are now firmly above 25C across much of the UK, the sunshine is hotter, noses are stuffy and the air is muggy, sometimes making it difficult to sleep. Keeping cool in a heatwave is a priority – but it also gives rise to various theories and myths on how to achieve this… Sleeping naked cools you down Sleeping naked seems like the easiest and quickest way to cool your body temperature down after being out all day. But this isn’t necessarily the case, according to Abbas Kanani, a superintendent pharmacist at Chemist Click Online Pharmacy. “Sweat collects on the body and remains there when we have no clothes on,” Kanani explained. “Although having less layers on the body can help you to feel more comfortable in the heat, wearing lightweight nightwear made from breathable fabrics helps draw sweat away from your body and makes you feel a lot cooler and more comfortable.” So what should you wear at night to keep cool? “Clothing made from natural fabrics like cotton or linen are breathable and absorbent,” Kanani recommended. “They will soak the sweat up off your skin and they let air through, which cools you down.” People don’t die from heat in this country The UK sun can feel different compared to when you are sunbathing and drinking cocktails on a beach in Barcelona – but that can catch people out. “The biggest myth is that the weather in the UK isn’t hot enough to be dangerous,” said Dr Adam Staten, a clinical director at One Day Tests and NHS GP. “Whilst we don’t have that many really hot days, when it is hot, it can be fatal. For example, during the heatwave last summer, hundreds more people died than normal for that time in the year.” Staten suggests we overcomplicate things when trying to keep cool. “Most measures are really simple and include common sense measures like keeping curtains drawn, keeping windows open or taking cool showers or baths.” Sticking to hot drinks will keep you cool Who else thinks drinking tea or coffee in hot weather will cool you down? For Staten, “One myth that seems to come up a lot is that hot drinks are better for cooling you down than cold drinks. I think the evidence actually shows that it doesn’t really matter – as long as you are keeping hydrated, your drinks can be hot or cold.” Pharmacist Kanani agrees with that final point. “Hydration is vital for keeping cool in hot temperatures. Drink plenty of fluids, especially water, to stay hydrated. Avoid excessive consumption of caffeinated or alcoholic beverages as they can contribute to dehydration.” You only need to wear sunscreen when the sun’s out Another common misconception is thinking that you can’t get sunburnt when it is cloudy outside. “This isn’t true,” Kanani said. “Although it’s less likely than when you’re out in full sunshine, clouds don’t block all of the sun’s UV rays.” It’s also why people either only apply sunscreen in the morning or none at all. “Many people think that when sunscreen is waterproof, it means they do not need to reapply it after swimming or sweating. It should be reapplied straight after you have been in water, towel drying, sweating or when it may have rubbed off.” Sunburn is something to be careful of. Staten said: “It’s really common and can actually be very severe both in the short term and for the longer term risk of skin cancer.” Read More Charity boss speaks out over ‘traumatic’ encounter with royal aide Ukraine war’s heaviest fight rages in east - follow live 7 hay fever hacks to ease your symptoms this summer The pests you really don’t want invading your garden and how to deter them How to take care of your mental health at festivals