The science of hydration and why eight glasses of water a day is a myth

As Britain gears up for a potential 30C heatwave, heat-related illnesses look set to rise alongside temperatures. But do you know how much water you really need for optimum health? Maria Lally talks to the experts to find out

The guidance says eight glasses of water a day is important for optimum health – but experts say the science is flawed (Getty)

Last year was the hottest year on record and all the signs are that 2024 will be even hotter. Swathes of southern Europe are battling unseasonably hot temperatures and the midwest and east coast of America are seeing the mercury soar past 37C.

Britain is also gearing up for a potential heatwave this week as temperatures are set to soar to 30C in some areas, according to the Met Office.

And with this comes new health concerns. Earlier this month, the popular TV presenter and author Michael Mosley died from heat exhaustion while walking back to his accommodation on the Greek island of Symi. Four other holidaymakers have lost their lives in similar circumstances in Greece in recent weeks, several others have been reported missing while hiking or walking and this week, Sicily has been turning away tourists due to the country’s brutal heat wave.