The Met Office has issued a red extreme heat warning for Wednesday and Thursday as the UK braces for temperatures of at least 39°C. The forecasters indicate that June's all-time daily temperature record is set to be broken. Amber extreme heat warnings have already been issued, covering much of southern and central England as well as much of Wales from Monday until the end of Thursday.
Hot Beverages May Offer Cooling Relief
While many seek cold drinks and ice lollies to stay cool, research from the University of Ottawa in 2012 suggests that hot beverages like tea and coffee might actually help lower body temperature in dry conditions. The study examined the impact of consuming hot drinks on body temperature and found that a hot drink can reduce the amount of heat stored inside the body, provided the additional sweat produced can evaporate.
Dr Ollie Jay, one of the study's authors, explained to the Smithsonian Mag: "If you drink a hot drink, it does result in a lower amount of heat stored inside your body, provided the additional sweat that's produced when you drink the hot drink can evaporate." The mechanism works because consuming a hot drink increases perspiration, and when sweat evaporates from the skin, it removes excess heat from the body.
Humidity Limits Cooling Effect
However, the cooling benefit only applies in dry conditions. In humid environments, the sweat cannot evaporate effectively, making hot drinks counterproductive. Dr Jay noted: "On a very hot and humid day, if you're wearing a lot of clothing, or if you're having so much sweat that it starts to drip on the ground and doesn't evaporate from the skin's surface, then drinking a hot drink is a bad thing. The hot drink still does add a little heat to the body, so if the sweat's not going to assist in evaporation, go for a cold drink."
Practical Advice for the Heatwave
As the UK endures extreme heat, residents are advised to consider the humidity levels. In arid conditions, a hot cup of tea may aid cooling, but in humid weather, cold drinks are more effective. The key takeaway is to stay hydrated and choose beverages based on the environment. The Met Office urges people to take precautions, including drawing curtains, seeking shade, and staying hydrated.
