As the UK enjoys a balmy summer with temperatures soaring above 25°C, health experts are urging the public to reconsider their go-to drinks, especially one particularly beloved beverage. While many Brits instinctively reach for an iced latte or cold brew to cool off, Dr Donald Grant, GP and Senior Clinical Advisor at The Independent Pharmacy, warns that coffee may do more harm than good during a heatwave.

“Even iced coffee can pose a problem,” Dr Grant explained.

They added: "The caffeine content acts as a diuretic, which increases urination and causes the body to lose essential fluids more quickly.”

In hot weather, when staying hydrated is crucial, this diuretic effect can increase the risk of dehydration, fatigue and even heat-related illnesses such as heat exhaustion or heatstroke.

“People often assume that iced coffee is a smart summer alternative, but the caffeine still triggers dehydration. If fluid loss isn’t replenished effectively, it can affect energy levels and cognitive function, and potentially become dangerous,” Dr Grant added.

Instead of caffeine-heavy drinks, Dr Grant recommends prioritising foods and beverages that support hydration and body temperature regulation.

Fruits such as watermelon and citrus, which are both high in water content, can be particularly beneficial.

Watermelon is made up of around 92% water and provides a natural cooling effect, while oranges and grapefruits, which are roughly 87% water, offer essential nutrients and a quick energy boost.

He also advised swapping out red meats and spicy foods, which can increase internal body heat and slow digestion.

“Red meat requires more energy to digest, which raises body temperature in a process known as diet-induced thermogenesis. Spicy foods, meanwhile, prompt sweating and can lead to further fluid loss.”

To stay properly hydrated, Dr Grant recommends drinking at least 2.5 to 3 litres of water a day, and more for men or those on medications that increase heat sensitivity.

“If drinking plain water is a challenge, try adding lemon, mint or cucumber to give it a refreshing twist,” he suggests.

So while the sunshine may be a welcome sight, Brits are being urged to think twice before sipping their daily coffee, and reach for hydrating, body-friendly alternatives instead.