Heatwaves hit Europe: How to stay cool when it really matters

Heatwaves can be dangerous, but simple measures can significantly reduce the risk of heat-related illness. Cities across Europe are expected to hit record summer temperatures in the coming days, with highs approaching 40°C in several regions. “Heatwaves are not just uncomfortable — they are one of the deadliest weather events in Europe, but most heat‑related illness is preventable with simple measures,” Tiago Villanueva, family physician and president of the European Union of General Practitioners / Family Physicians, told Euronews Health. During extended periods of heat, the body’s ability to regulate its internal temperature and eliminate excess heat is compromised, increasing the risk of heat exhaustion and heatstroke. The effort required to cool the body also places additional strain on the heart and kidneys, meaning extreme heat can worsen existing health conditions. As Europe braces for another heatwave, here are some tips to stay cool and safe. Keep cool during the hottest hours Temperatures are expected to exceed 30°C across much of Europe this summer, with many areas also experiencing tropical nights. A tropical night occurs when temperatures do not fall below 20°C, preventing the body from recovering from daytime heat. The lack of overnight cooling can place severe strain on the cardiovascular system, disrupt restorative sleep, and increase mortality rates. During the day, experts recommend staying indoors during the hottest hours, keeping windows and shutters closed to block out the sun and ventilating homes during the cooler morning and evening hours. The World Health Organization (WHO) recommends using electric fans only when temperatures are below 40˚C. Above this threshold, fans will circulate hot air and heat the body. Avoid going outdoors during the hottest part of the day whenever possible. If going outside is unavoidable, loose-fitting, light-coloured clothing made from breathable fabrics such as cotton or linen is recommended. These materials are also suitable for bedding, helping to keep the body cool during hot nights. Beyond keeping the body cool, clothing also protects the skin from harmful ultraviolet (UV) radiation. Protect yourself from the sun Avoid direct sun exposure, particularly during the middle of the day and apply sunscreen every two hours. This helps maintain the skin’s protective barrier, reducing the risk of sunburn and skin cancer. Watch for signs that the sunscreen needs reapplying, such as skin that feels dry, looks red or feels burnt. If you plan on being in the sun during the central hours of the day, protect your head with a hat or cap to prevent the sun from hitting it directly. Eyes and eyelids are also sensitive to the UV rays. Wear sunglasses to avoid dangerous exposure and reduce the risk of eye damage. Look for sunglasses with specific UV protection. According to Bryce St. Clair at Johns Hopkins Medicine, the colour lens also matters: brown, green and grey lenses are best while yellow lenses provide less protection. Stay hydrated Drinking water and other fluids regularly is key to keeping the body hydrated during hot days. The WHO recommends drinking at least two to three litres of water a day. It is very important not to wait to be thirsty, said Villanueva. He also advises avoiding excessive alcohol and caffeine, as they can act as diuretics and worsen dehydration. Watch out for ‘red flags’ Even when taking all the necessary precautions, it is possible to feel unwell during extreme heat. Experts recommend watching for early warning signs that could indicate heat exhaustion or the onset of heatstroke. Symptoms include dizziness, nausea, fatigue, weakness and confusion. If someone is experiencing these symptoms, it is the moment to cool down, take a shower or bath, spray water, drink fluids and seek medical advice if symptoms worsen. Who is most at risk? Not everyone is equally vulnerable to the extreme temperatures. “Those at higher risk include older adults, especially over 65, people with chronic diseases, infants and young children, socially isolated individuals, outdoor workers and homeless populations,” Villanueva noted. Children sweat less per kilogram of body weight and have a higher metabolic rate, causing them to heat up more quickly during periods of extreme temperatures. People on medication are also at a higher risk. Some prescription and over-the-counter medications can interfere with the body's ability to regulate temperature, sweat or stay hydrated.