You Could Be Driving Like You’re Drunk Just From Mild Dehydration!

And while your aircon might be keeping you nice and cool, it’s actually making things worse!

It’s summer in Britain. Yes, actual summer – it’s our THIRD HEATWAVE so far this year!. That means barbecues, ice cream vans, and… dangerously dehydrated drivers. Wait, what? Yes, really.

You might think you’re safe and sound, cruising along in your climate-controlled motor, cold air gently blasting your cheeks, enjoying life with the smug satisfaction of someone who ticked the “dual-zone AC” box. But while you’re sipping that fizzy drink or half-lukewarm coffee from the services, your driving ability is deterioting rapidly, you won’t even realise it, until its too late!

Mild Dehydration = Major Danger

According to a Loughborough University study in collaboration with the European Hydration Institute, drivers who were just mildly dehydrated (we’re talking a 1–2% loss of body water – so nothing extreme) made twice as many driving errors as those who were properly hydrated – twice as many mistakes! That’s the same level of impairment as having a blood alcohol content of 0.08% – the UK’s legal limit for drink driving.

We’re not talking heatstroke or fainting. We’re talking:

• Slower reaction times
• Poor concentration
• Mood swings
• Lane drifting
• Missed signals
• Dodgy decision-making

But I’ve Got Air Con – I’m Fine, Right?

Not really. Here’s what most people don’t realise about AC: air conditioning works by removing heat and moisture from the air. That means it creates a dry, low-humidity environment inside your car. Crisp and cool, sure – but potentially drier than the Sahara Desert on some days!

Inside that dry box on wheels, your body is slowly losing moisture through a process called insensible water loss – you don’t even notice it. You’re breathing, your skin’s evaporating water, and over a two-hour motorway run, you could already be dehydrated enough to compromise your driving. There’s also transepidermal water loss – a posh term for water loss directly through your skin. Again, no sweating required. It’s like being stealth-drained.

Coffee and Cola? They’re Not Helping!

When the slump hits, you might reach for a cold can of something sugary. Or a coffee to perk you up. But both caffeine and fizzy drinks are part of the problem.

Caffeine is a mild diuretic, meaning it tells your kidneys to send more fluid to your bladder – and it makes you want to pee more frequently. Some studies say it doesn’t dehydrate habitual coffee drinkers that much, but mix in a bit of heat and a dry AC-blasted cabin – and suddenly that caffeine buzz becomes a dehydration bomb.

And don’t get me started on sugary energy drinks. A short-lived sugar high followed by a hard crash is no good for staying sharp behind the wheel.

So What Should You Do?

Glad you asked. Here’s a crucial summer hydration checklist for drivers:

• Water, water, water – keep a bottle in your car at all times
• 500ml for short trips, at least 1 litre for longer drives
• Hydrate before you start driving – don’t wait until you’re gasping
• Use a reusable bottle with a straw or flip top – easier to sip while driving
• Avoid sugary drinks and too much caffeine
• Take breaks every 1.5 to 2 hours – stretch, cool off, hydrate, repeat
• Consider hydration drinks with electrolytes (sodium, potassium, magnesium) – but avoid the ones packed with sugar and chemicals

This Isn’t Just a Health Tip – It’s a Road Safety Alert

Dehydration doesn’t come with flashing red warning lights. You won’t feel dizzy or lightheaded straight away. You’ll just start making small mistakes. And those can turn into big consequences when you’re behind the wheel.

That’s why this isn’t just a wellness PSA – this is about keeping yourself, your passengers, and others on the road safe.

Let’s Raise Awareness

Have you ever felt sluggish or zoned out on a summer drive – even with AC on full blast? Think it was just “the heat”?
Tell me your experience in the comments. Let’s get this conversation going.

And please – share this with friends and family. Especially anyone planning road trips, staycations, or long commutes this summer. You could genuinely be helping prevent accidents.

Like, share and subscribe if you haven’t already – and stay tuned for more real talk on motoring, safety, and all things four-wheeled. Stay cool. Stay hydrated. Stay safe.

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