If you live in the UK, it’s time to dig out the sun cream, as a heatwave is set to hit us this weekend and into next week.
With parts of the UK expected to bask in temperatures of up to 91°F (33°C), you may be concerned about keeping cool.
A quick Google search for ‘how to keep cool in a heatwave’ will bring up a range of weird and wonderful measures, including drinking hot tea, eating spicy food, and even licking your wrists.
But do any of these methods actually work?
Ahead of the heatwave, MailOnline has delved into the science behind these wacky cooling methods, to help sort the fact from the fiction.
While you might be tempted to reach for a cold drink to help cool you down, surprisingly hot drinks such as teas and coffees may actually be more effective
1. Drink hot tea
While you might be tempted to reach for a cold drink to help cool you down, surprisingly hot drinks such as teas and coffees may actually be more effective.
A study in 2012 by researchers from the University of Ottawa looked at the effect of drinking hot drinks on body temperature.
The results revealed that a hot drink can cool you down – but only in dry conditions.
Speaking to the Smithsonian Mag, Dr Ollie Jay, one of the authors of the study, explained: ‘If you drink a hot drink, it does result in a lower amount of heat stored inside your body, provided the additional sweat that’s produced when you drink the hot drink can evaporate.’
When you ingest a hot drink, you start sweating more. If the sweat can evaporate, it cools you down – more than compensating for the added heat to the body from the fluid.
While sweating can be embarrassing, it’s an essential bodily function to help keep us cool.
As the sweat evaporates from the surface of your skin, it removes excess heat by converting the water from a liquid to a vapour.
However, in humid conditions this cooling effect is less effective, so drinking hot drinks won’t help to cool you down.
Dr Jay explained: ‘On a very hot and humid day, if you’re wearing a lot of clothing, or if you’re having so much sweat that it starts to drip on the ground and doesn’t evaporate from the skin’s surface, then drinking a hot drink is a bad thing.
‘The hot drink still does add a little heat to the body, so if the sweat’s not going to assist in evaporation, go for a cold drink.’
2. Eat spicy food
Instead of grabbing an ice cream, you might want to opt for a spicy curry this week.
The ‘burn’ you feel in your mouth from eating spicy food is caused by capsaicin – a chemical found in chillis.
This is usually followed by a similar warming sensation across the rest of hte body, causing you to sweat.
Writing in Scientific American, Yale Professor Barry Green explained: ‘Spicy foods excite the receptors in the skin that normally respond to heat.
The ‘burn’ you feel in your mouth from eating spicy food is caused by capsaicin – a chemical found in chillis. This is usually followed by a similar warming sensation across the rest of hte body, causing you to sweat
‘The central nervous system reacts to whatever the sensory system tells it is going on.
‘Therefore, the pattern of activity from pain and warm nerve fibers triggers both the sensations and the physical reactions of heat, including vasodilation, sweating, and flushing.’
As we saw with drinking hot drinks, sweating is one of the key methods to help regulate your temperature – so tea and curry it is!
3. Lick your wrists
It’s a tactic used by several creatures in the animal kingdom, including kangaroos and monkeys.
And as disgusting as it sounds, licking your wrists also works to help keep humans cool.
The wrists contain pulse points – areas where you can feel your pulse because your blood vessels are close to the surface of your skin.
By licking your wrists, you’re using saliva to mimic the effects of sweat, cooling the surface of the skin.
This slows the flow of blood, stopping your body from overheating.
If the idea of licking your wrists doesn’t appeal, you can also pour water on your wrists for a similar effect.
4. Unplug your chargers
While most of us know that big, powerful electronics like TVs and computers generate a lot of heat, you might not think to unplug smaller applicances.
Lamps, kettles, irons and even chargers can generate a lot of heat if they see heavy use.
In 2020, researchers from ZDNet put a wireless charger to the test, using a thermal camera to study how hot it was, both in and out of use.
They found that when an iPhone 11 Pro Max was placed on the wireless charger, the device reached 32°C, while the surrounding air hit 20°C.
‘If you want the charging to be cooler, remove any cases, don’t charge the phone in direct blazing sunlight, and keep the pad on a hard surface (not on blankets or anything that might block the air holes),’ they advised.
While most of us know that big, powerful electronics like TVs and computers generate a lot of heat, you might not think to unplug smaller applicances like chargers
5. Ditch the booze
You might be tempted to head for your nearest pub garden during the heatwave, but if you do, try to lay off the booze.
Alcohol is a diuretic that causes you to urinate more, and can leave you severely dehydrated.
‘Alcohol makes us pee more and more frequently, and fluid leaving our bodies at this rate can lead to dehydration if not replaced,’ Drink Aware explains.
‘It is important to replace lost fluid by drinking water if we choose to drink alcohol.
‘The effects of dehydration include feeling thirsty, dizzy, lightheaded and tired, experiencing a dry mouth and lips and dark yellow and strong-smelling pee.’
Alcohol also causes the blood vessels in your skin to dilate, making you feel hotter.
It may sound counterintuitive, but research suggests that you shouldn’t open all the windows to keep your house cool
6. Don’t open all the windows
It may sound counterintuitive, but research suggests that you shouldn’t open all the windows to keep your house cool.
Hot air rises, which means sunny upstairs rooms will be warmer than those that are downstairs in the shade – setting up a pressure difference.
By opening windows in these rooms, you can create a strategic breeze that draws in cool air from downstairs, and forces warm air out of the house through the sunny upstairs rooms.
The idea of breathing yourself cooler may sound ridiculous, but seasoned yoga experts swear by a technique called shitali pranayama
7. Roll your tongue and breathe
The idea of breathing yourself cooler may sound ridiculous, but seasoned yoga experts swear by a technique called shitali pranayama.
Speaking to Live Science, Meera Watts, founder of Siddhi Yoga, explained how the technique can cool your body down within minutes.
‘It starts with sitting in a comfortable position with the back straight and keeping the hands on the knees,’ she explained.
‘Taking out the tongue and folding it on the sides like a U shape. You’ll have to inhale through your tongue in this tube position and exhale with your nostrils.
To feel the cooling sensation, repeat it 5-8 times which will take no more than a few minutes.’
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