That means you shouldn’t rigidly stick to the two-litre rule or the gallon challenge. “The guidance about drinking 1.8 to two litres a day is based on the need to replenish the quantity of fluids most adults lose on an average day in average temperatures… but the average is only a guideline.”

How to stay hydrated

Staying hydrated is important, but you don’t need excess amounts to reap the skin, gut and energising benefits.

There are more efficient ways to monitor your hydration levels than forcing yourself to drink. “Pay attention to your body’s cues, including your thirst levels. You can count hydration levels in food, tea and coffee and make sure to carry a water bottle with you when you go out,” says Dr Young.

Staying hydrated in the heatwave is unarguably important, but you can have too much of a good thing.

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