The UK is enduring its fourth heatwave of summer 2026, with temperatures exceeding 35C across three consecutive months for the first time on record. Half of England is now in drought, prompting experts to advise on how much water to drink during the relentless heat.
According to Reach PLC's consultation with doctors and nutritionists, the general consensus is that people should consume between 2.5 and three litres of water daily during a heatwave. This exceeds the conventional two-litre recommendation as temperatures climb.
Expert Advice on Hydration
Dr Nikki Ramskill, Women's Health GP at The Female Health Doctor, noted that individual needs vary. She said: "It's very individual. People should keep an eye on the colour of their urine to see if they are dehydrated, it should not be dark coloured." She added that symptoms like dry skin and aching joints may indicate dehydration, and hydration can also come from coconut water, sugar-free squash, and ice lollies.
Physiotherapist Phil Evans supports this guidance, advising up to three litres per day. He emphasised "getting ahead" of thirst by sipping little and often, and noted that foods like watermelon, cucumber, and apples contribute to hydration. "Dehydration hits your joints before you feel thirsty. During hot weather, it's easy to become mildly dehydrated without noticing, which can leave joints feeling stiffer and less comfortable," he said.
Individual Intake Varies
Nutritional biochemist Jamie Christie stated adults should target two to three litres daily during a heatwave, adjusting for activity and perspiration. "It's hard work. We should increase it slightly, as the more we sweat or the higher our breathing rate rises to help cool us down, the more water we'll lose," he said. He recommended small sips throughout the day and aiming for pale straw-coloured urine.
Registered nutritionist Natalie Rouse of Free Soul advises two to 2.5 litres daily, increasing by 300-700ml in hot conditions. She suggested "front loading" hydration by drinking substantial fluids in the morning. "People should be doing this all year round but especially in really hot weather," she added.
NHS Heatwave Advice
The NHS recommends staying in the shade between 11am and 3pm, applying sunscreen, avoiding strenuous exercise, and consuming cold food and beverages. It also advises avoiding alcohol, caffeine, and hot drinks to stay safe during extreme heat.
