As the UK basks in sweltering temperatures, health officials are sounding the alarm about the dangers of drinking in the heat. From Paris's temporary ban on public booze to a four-fold surge in cardiac arrests, the pressure on emergency services is mounting.
Alcohol can be particularly hazardous when temperatures soar, thanks to its diuretic properties. It prompts the body to produce more urine, leading to fluid loss. Research shows that every 1ml of alcohol can trigger the production of around 10ml of urine – a worrying trend, especially for strong spirits like whisky. A 25ml measure containing 10ml of booze could result in a net water loss of 85ml after urination.
But what about beer? A pint (568ml) of 5% brew contains approximately 28ml of alcohol, stimulating around 280ml of urine production. However, it also contains roughly 260ml of water, potentially leaving drinkers more hydrated than they'd be without a drink at all – according to Professor Ron Maughan from the University of St Andrews. That said, downing multiple pints can swiftly turn this effect on its head, leading to dehydration due to excessive urination.
The heat and booze combo puts huge strain on the heart. Hot weather causes blood volume to drop as the body sweats more, while widened blood vessels near the skin help dissipate heat – but alcohol makes these changes worse still. This can lead to dizziness, collapse, or even a heart attack in extreme cases, particularly if dehydration disrupts heart rhythm further.
And it's not just cardiovascular risks we need to worry about: drinking in a heatwave significantly raises the risk of heatstroke, as dehydration and alcohol impair the body's ability to regulate its core temperature. This can also make people less likely to spot warning signs like slurred speech, headaches, nausea, or an racing heart – all symptoms that experts like Professor Helmut Seitz from the University of Heidelberg say we should be on the lookout for.
While the message is one of caution, Professor Maughan suggests that complete abstinence may not always be the most practical advice. If people are discouraged from drinking altogether, they might not make up for lost fluids with water or other non-alcoholic drinks – potentially leading to more harm than good.