Driving in a heatwave: Top 8 tips for UK motorists

• Top 8 tips for driving through a heatwave
• Advice for motorists travelling in hot summer weather
• From staying hydrated to checking your tyre pressures
• Hot weather can also increase the road rage risk

Driving in heatwave conditions poses unique risks for UK motorists - and here's how you can weave a path through the potential dangers.

Whether it's your regular commute to work or its a long summer trip, hitting the road when it's cracking the flags can pose real challenges.

From cooling your car before you get in it, to ensuring the wellbeing of passengers and pets, travelling in hot weather can cause temperatures to rise in more ways than one. 

Here we offer some practical tips that might also help you stay the right side of the law. 

Stay hydrated

It should go without saying that staying hydrated during a heatwave is paramount. 

But if you're embarking on a long journey with the family in tow, you might be tempted to avoid drinking lots of water in a bid to avoid any extra toilet pit stops. 

That's an extremely bad idea - particularly if you're behind the wheel. 

Back in 2015, academics at Loughborough University published research that examined what happened to drivers when they were in a state of 'hypohydration' - aka, having low body water levels. Using a driving simulator, the boffins observed a 'significant increase in minor driving errors during a prolonged, monotonous drive' in dehydrated test subjects. 

And the experts even likened the slump in driving standards to those experienced 'following the ingestion of an alcoholic beverage' or 'while sleep deprived'. 

Long story short, don't skimp on the water if you want to stay safe. 

Ventilate your car before setting off

^{(Air vents in the second row - crucial in a heatwave)}

If you've got an electric vehicle, you might be lucky enough to have cabin preconditioning; a couple of taps on an app and you can pre-set your climate control to ensure your car's interior is glacially cool before you set foot inside.

For others, getting the car's cabin to an acceptable temperature can be more problematic - particularly if you're inside and waiting for the air con to kick in. 

You might be tempted to leave your car's engine idling with the air con on to cool it down prior to setting off. You're unlikely to be prosecuted for doing that if the car is on your own private driveway, but it's a different story if you're on a public road - with fines of up to £110 in some cases. 

There is, though, another potential hack. 

^{(Chilled out in the too-cool-for-school CUPRA Formentor)}

British maths professor and and science broadcaster Hannah Fry recently revealed a top tip which involves opening your car's rear window on the opposite side of the driver's door before opening and closing the driver's door quickly. 

The laws of fluid dynamics dictates that the warm air is drawn outwards to be refilled with cooler air from outside. 

Does this trick actually work? Well, we gave it a whirl and experienced mixed results - but we did do it when the air outside the car was just as stifling as the air inside it, so it might not have been the best test scenario! 

Wear suitable sunglasses

Sunglasses aren’t just a fashion statement, they're crucial protecting your eyes while you drive.

Experts at the AA suggest you choose your sunglasses extremely carefully, as some can be too dark for driving. There are two essential requirements needed in lenses used for driving:

• Vision must remain clear
• Sufficient light to let you see properly must get to your eyes

It is also recommended you have an eye test every two years to check if you need prescription glasses, as driving without glasses when required is illegal and can invalidate your car insurance and lead to a hefty fine.

The OTHER big thing to remember is that trying to dig out a pair of sunnies from the bottom of your glove box while driving - and then trying to clean the smudged lenses with one hand while the other is on the wheel - poses obvious dangers. Make sure your shades are clean and placed somewhere handy for when you need them most. 

Ensure your screen wash is full

It's a simple thing to miss, particularly if you haven't needed to use your wipers in a while because of the warmer weather. 

But summer driving can mean bug splats, bird faeces, and suddenly obstructed windscreens. Bursts of Saharan dust, blown in from North Africa, are pretty common in the UK, too. 

Always make sure your screen wash bottle is topped up before you set off. 

Protect pets

Dogs and hot cars do not mix. And there are a few things to be mindful of when it comes to travelling with your pooch. 

Firstly, don't let Fido stick his or her head out of the window, no matter how much they might want to. Besides the risk of collision, they can get dirt and debris in their eyes and their ears, and if they’ve got their head out of the window, they probably aren’t properly restrained, either.

Dogs are also really susceptible to air pressure changes in your car's cabin. The throbbing sensation you get when just one window is open can be extremely uncomfortable for dogs with their sensitive hearing. 

^{(Author's own pooch, looking slightly hot and bothered after a car trip)}

Beware warm air trapped in boots, too, as cool air from your climate control system isn't usually blown into the boot through dedicated vents. 

Finally, never set off unless you've got at least a couple of litres of water with you. The water also needs to be room temperature - not ice cold - because really cold water can cause dogs to go into shock. 

When it comes to this particularly author and dog owner (hello, Cooper, my fun-loving Cockerpoo), I don't leave home without our doggy water bottle with an integrated bowl at the end of it. For quick drinks to keep him cool when we're on the go, it's an absolute lifesaver. 

You can read our definitive guide to doggy car travel here. 

NHS advice for travelling with children

Use window shades on side windows to protect against direct sunlight, keep the cabin cool, and dress children in light, loose-fitting clothing. 

Frequent stops are a must, don't leave youngsters in car seats for too long, and be on the lookout for tell-tale signs of heat-related health issues. 

Never cover a car seat with a blanket to block out the sun, as it can trap heat and cause temperatures inside to rise quickly, increasing the risk of overheating.

And do not leave children unattended in a hot car.

Another thing to be mindful of is the risk of scorching-hot belt buckles and plastic car seat parts, super-heated from being in direct sunlight. It's a very real phenomenon that's been documented in the scientific literature and poses a horrifying burn risk.

Beware summer road rage

^{(Our automotive writer Tim Barnes-Clay keeping his cool)}

Keeping your cool in a heatwave is a tricky task, in more ways than one. 

It's easy for tempers to fray when motorists are hot and bothered, so be mindful that everyone makes mistakes and try not to lose your cool - or let other hot heads impact you - if errors are made.

Becoming agitated when on the road can also see you falling foul of the law. Actions such as aggressively honking your horn, gesticulating to other road users, or screaming out of your window, can attract up to nine points and your licence and a potential £1,000 fine.

What's more, one Spanish study from 2015 estimated the risk of crashes 'significantly increased' by 2.9% during heat wave days. Stay safe out there.

Keep an eye on tyre pressures

When outside temperatures fluctuate rapidly - going from heatwave to cooler conditions - the pressure inside your car's tyres can change, too. 

Hot weather can increase tyre pressure, while colder weather can cause it to fall. For every 10 degree C shift, tyre pressures might go up or down by around 1-2 PSI. 

That might sound like a small fluctuation, but it could still have a knock-on effect when it comes to handling, braking distances, fuel efficiency, tyre wear and safety in general. 

When tyres are underinflated, you could experience excessive heat build up, potentially leading to tyre failure, the serious consequences of which are all too obvious.

Overinflated tyres, meanwhile, could again reduce braking distances on some surfaces while you’re also at a greater risk from pothole damage, as the tyre is less able to absorb the impact of road craters. 

The good news is that modern cars will warn you when tyres are underinflated. If you see an illuminated symbol on the dash that looks like a flat tyre with an exclamation mark inside it, do not ignore it. 

If you can, check your tyre pressures when they’re cold in order to get an accurate reading. You can often find the correct tyre pressures on a sticker inside the driver’s door frame or fuel filler cap - or simply check the owner’s handbook. 

You can check the pressure itself by using a digital gauge, an air compressor at home, or making use of the air pumps that you’ll find at most petrol stations. 

If your vehicle has a full-size or space-saver spare wheel, check its pressure too. It's easy to forget until you actually need it.

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