Which Drinks Truly Hydrate During Extreme Heat

Paris – 07/06/2026: During persistent heat, regular drinking is the most important preventive measure against dehydration – preferably before thirst arises. French health authorities such as Santé publique France emphasize that fluid and salt losses from sweating must be continuously compensated. Insufficient intake can lead to fatigue, dizziness, headache and, in extreme cases, heatstroke with circulatory collapse.

Water is recommended as the standard. Tap water is considered safe in France and is sufficient for daily use. Those who find the taste monotonous can choose unsweetened herbal tea, diluted fruit juices or water with a slice of lemon. The decisive factor is regularity: small amounts at short intervals are better tolerated than large amounts rarely. Very cold drinks offer no proven additional benefit compared with cool to lukewarm drinks and can cause stomach complaints in sensitive individuals.

With increased sweating – for example during physical work, sport or in poorly cooled spaces – sodium supply is particularly important. Salty drinks, clear broths or suitable oral rehydration solutions are recommended. For people who train for longer or intensively, electrolyte drinks with a moderate amount of sugar may be appropriate; these should provide a balanced ratio of water, sodium and carbohydrates. For infants, older people and chronically ill patients: a drinking plan with small, frequent portions, possibly supplemented with electrolyte solutions recommended by a doctor.

Not suitable are heavily sweetened soft drinks, highly concentrated fruit juices without dilution, alcohol and very caffeine-rich drinks. They can increase water excretion, suppress the feeling of thirst or adversely affect blood sugar levels. Iced coffee, energy drinks and highly concentrated yerba mate or black tea should therefore be consumed only in small amounts during heat. So-called detox or “miracle” waters also do not replace a balanced intake of fluids and salts.

Warning signs of dehydration are a dry mouth, dark urine or reduced urine output, dizziness, muscle cramps, unusual fatigue and confusion. At such symptoms drink immediately, preferably water or a suitable rehydration solution. If complaints persist or vomiting, impaired consciousness or very low urine output occur, seek medical help immediately.

In addition to drink choice, basic tips remain important: reduce physical exertion, wear light clothing, cool or shade rooms, ventilate regularly and use fans or air conditioning sensibly. Families, neighbors and caregivers should pay extra attention to infants, very elderly people and those living alone. Up-to-date guidance and heat warnings are continuously published by Santé publique France, the health insurance fund Ameli and the Ministry of Solidarity and Health on their information websites.