Where I grew up, snow days were a foreign concept. Instead, children looked to the other end of the thermometer when hoping for a day off school. Playground rumour had it that when the temperature reached more than 40C, classes would be cancelled.

I finished primary school at the turn of the century, so never saw that theory tested. But as the climate crisis intensifies, throughout much of south-eastern Australia, we’ve come to expect at least one 40C day each summer. That means subsequent cohorts of Australian children are learning that temperature triggers for school closure were only ever an urban legend. Instead, in many schools, hot weather means staying indoors during break and lunch.

Meanwhile, Australians barely break a sweat at a string of 28C days, the UK Met Office’s highest threshold for a heatwave. This isn’t because our bodies are different, says Prof Ollie Jay, director of the Heat and Health Research Centre at the University of Sydney. It’s because we’ve learned to adapt our behaviour.

Many of us also rely on air conditioning, and thanks to solar panels and batteries, some of us don’t even pay for it. Given air conditioning is energy-guzzling, I’ve focused on other, more environmentally friendly, ways to keep cool. However, for some people, aircon can quite literally save lives, so I’ve included details at the end about it.

With temperature records likely to break in parts of Britain this week, here’s how to handle the heat like an Australian.

How are you coping with the heat? Let us know your best tips by emailing thefilter@theguardian.com.

How to keep cool in a heatwave

Draw the curtains

Keeping a home comfortable in hot weather means keeping heat out when temperatures peak, then bringing cool air in when they fall. Stuart Walker, a research fellow in sustainability assessment at the University of Sheffield, suggests closing the curtains on hot days.

“If the sun enters a room over a period of time, it will heat up and then it will stay hot,” Walker says. “So don’t respond when the room is already hot. You need to have responded nine hours ago when the sun was first shining in that room.”

Shielding your home from direct sunlight is a daily routine in Australia. As soon as the sun comes in – or before that if we’ll be out for the day – we close the blinds; the habit is ingrained.

Consider a blind

Honeycomb blinds, like Duette, are particularly good for stopping heat gain, and as a bonus they also stop heat loss in winter. Their insulative properties are due to a cellular shape, which traps air pockets, creating a thermal barrier between indoors and out.

Because blinds sit in the recess of your windows, they take up less floor space than curtains, which makes them a good option for smaller spaces. They are also easier to clean. For floor-to-ceiling windows, vertical blinds aren’t as efficient as honeycomb styles because they don’t trap air, but they are cheaper, and allow you to adjust for the angle of the sun throughout the day. For smaller windows, venetian blinds are similarly flexible, though in my experience less durable. For renters, Shade and Story also make clip-on blinds.

Curtains come in a wider variety of colours and styles than blinds, and they tend to look better in many spaces. Thermal curtains – which have a layer of insulation – are the most efficient style, especially if they have a pelmet to trap air. But be wary of darker colours: instead of reflecting heat like lighter hues, they absorb it, and can end up acting like radiators when the sun is fierce.

Let the night air in

Once the sun goes down, it’s time to open up the windows and let the heat out. If it’s possible to open doors and windows on different sides of your home, this will create a cross-breeze, which is particularly effective for cooling.

To that end, consider installing another Australian essential: fly screens. These allow windows to stay open all night without letting pests inside. I have a pleated fly-screen door – like those made by Phantom Screens – leading out to my flat’s balcony. It makes a big difference to our cooling bill, and slides out of sight when not in use. Renters can use magnetic fly screens that don’t require any installation, or Velcro fly screens, which are sturdier but may leave lasting scars on your window frames. Both are available cut-to-size from New Blinds.

If you’re lucky enough to live in a house with multiple bedrooms, Walker suggests switching where you sleep during summer. The coolest rooms in your house are likely to be north-facing with small windows. If you live in a multistorey home, the coolest spots will most likely be on a lower floor, because hot air rises. If you live with children or vulnerable people, Walker advises prioritising their needs by moving their beds to the coolest room.

Create a breeze

The final thing to buy well before it gets hot is a good fan, since stock gets low when temperatures rise. Sydney’s Prof Ollie Jay says that as long as the temperature is below 40C, “fans are effective at reducing how hot people get”. Above 35C, fan use can become detrimental. At his Thermal Ergonomics Laboratory in Sydney, they tested fans in 45C, 15% humidity conditions and found they “accelerated how quickly [people] heated up”.

Even though fans don’t change the temperature, air movement across the body “can massively increase the capacity for evaporation”, and evaporation is how human bodies stay cool.

Jay and his team use large pedestal fans for their studies because this model creates the greatest airflow. “The bigger the fan, the better, basically,” Jay says. Smaller desk fans and portable fans can help with your perception of heat, since they move air across the face, where you “have a lot of sensors that detect heat and cold”, but smaller fans’ “effect on whole body heat loss is not going to be sufficient to make a big difference,” he says.

Devola Platinum Low Noise DC 9in fan

Vornado 133 small room air circulator fan

In the Filter’s test of the best fans, Devola’s desk fan was the best budget option. In Australia, the Vornado, which is available in the UK too, has developed something of a cult following for being relatively quiet and good-looking. It’s also safer to use around children with small, searching fingers – not always the case with classic bladed fans.

Get up early

It’s not a coincidence that Australians are among the world’s earliest risers: we try to get up before the temperature does. On hot days, exercising, walking the dog and aggressively watering the garden are all best done just after dawn; so set your alarm accordingly. Once those tasks are finished, shut your blinds and close the doors to south- and west-facing rooms to stop heat entering the rest of the house.

Dress for the weather

Women’s 100% premium linen shirt

Men’s 100% premium linen shirt

In theory, the best outfit for a hot day is your birthday suit, says Jay, since more exposed skin allows for better evaporation. As you can’t leave the house naked, loose-fitting garments made from natural fibres are next on the list. While clothing with sweat-wicking properties might seem like a good idea in the heat, and can be more comfortable than clothes that are damp from sweat, wicking garments are “not so good for keeping cool,” says Jay.

Wicking fabric draws sweat away from your skin, so “it basically reduces the amount of heat [extracted] from the body … for a given amount of sweat that you evaporate”. It’s fine to wear wicking underwear, Jay says, which is “good for comfort”, but for outer layers, pick clothes made from 100% cotton, linen or a blend of the two. Lighter-coloured tops are preferable if you will be out in the sun, since darker shades absorb more heat. Uniqlo has reasonably priced linen shirts for women and men.

For bottoms, choose something loose-fitting, such as this cotton skirt from Arket, or this shirt dress from Boden, both of which are now reduced, or these lightweight linen-blend trousers for men from Marks & Spencer.

Keep your fluids up

The Filter’s favourite water bottle: Owala FreeSip

Pack a full water bottle before you leave the house, and drink more than you think you have to. The amount of liquid you need varies a lot by your size, gender and activity level, but Australian guidelines suggest at least 2.5 litres for men and 2.1 litres for women. In the UK, the NHS Eatwell guide reads “aim to drink 6 to 8 cups or glasses of fluid a day”, which is about 1.2 to 2 litres.

For more, read our guide to the best water bottles from our test of 42

The Filter’s favourite travel mug: KeepCup Commuter

“Staying as hydrated as possible is critical,” Jay says. Tea and coffee can be part of that fluid intake. There’s no evidence caffeine needs to be avoided in the heat, Jay says, as caffeine’s diuretic effect is “weak”.

If you want to order coffee to go like an Australian, ask for a latte over ice; and if you want that ice to stay frozen, have the barista pour it into a travel mug. They’re as good at keeping drinks cold as they are at keeping them hot.

Unlike caffeine, alcohol can be a problem. If you’ve been drinking the night before a hot day and you’re a bit dehydrated, “you could suffer a bit”, Jay says, especially if you’re doing something strenuous. If you’ve been drinking, or sweating a lot, specifically designed hydration products like Hydralyte, which contains a balance of sugar and electrolytes, can help. It also comes in icy pole form, for a bit of cooling fun.

Stick to the shade – of a tree, if you can

When you’re out and about, keep in mind that the temperature forecast is taken in the shade. When walking outdoors, cross to the shady side of the street, and pick the park bench under a tree to eat your lunch. City trees have natural cooling properties, and parks with layered shrubs and ground cover (like grass) are even better because they reduce radiant heat as well as creating shade.

… or bring the shade with you

Straw visor

Cotton-linen wide-brim hat

Between 11am and 3pm, avoid the sun entirely if you can. Not just because it will make you hot, but also because it will burn you. In Australia, even the beaches clear out when the UV index reaches its peak, which is often as high as 13. With fair skin in those conditions, no amount of sunscreen will save you.

In the UK, summer UV highs are typically closer to 7; but that is still more than enough ultraviolet light to turn a pale person into a tomato the next day. The darker your skin tone, the lower your burn risk generally, but there are many medical conditions that can make ultraviolet light harmful for people with dark skin too.

If you have to be out and about, wear a hat with a brim wide enough to shade your whole face. My all-time favourite is this bucket hat from Lack of Color because it’s got a huge brim, a tie to keep it on in the wind, and it travels well because it is made of cotton. In the UK, Uniqlo’s cotton-linen wide-brim hat, above, is a close match.

If you don’t need to stuff them in luggage, Australian brand Helen Kaminski makes beautiful, if pricey, straw hats for all. Its visors are terrific for avoiding hat hair too: M&S does a great version in the UK.

I’ve spent the last decade searching for a non-dorky, wide-brim, travel-friendly hat for my husband, to no avail. If you find a good one, please email us. In the meantime, Solbari does a good range, available in the UK.

All-weather umbrella

While it’s a more common sight in south-east Asia than Australia, parasols also offer whole-body shade. Davek and Blunt are known for their durable umbrellas, and make UPF-rated parasols; Muji has more affordable all-weather umbrellas. Just pick a light colour so it reflects the sun, rather than drawing heat down on your head.

Lower your temperature

A big drink of cold water won’t just keep you hydrated, it will also lower your temperature – so that’s the first thing to try when you’re feeling too hot. If you arrive in the office sweltering from your commute, splashing cool water on your face gives some instant relief while you wait for the air conditioning to work its magic. If you’re wearing makeup, apply a soaked hand towel to the back of your neck instead.

During the day at home, dousing yourself with cold water or putting on wet clothes are both evidence-based, low-energy cooling methods – especially when combined with sitting in front of a fan. Jay says there’s a difference between “thermal sensation” – our perception of heat – and our actual body temperature. Cooling your face or feet makes a big difference to thermal sensation because you have lots of blood flow to those areas, but in Jay’s lab they have found cold foot baths are only moderately effective for lowering core body temperature. “It definitely reduces how hot you feel, but it doesn’t necessarily reduce how hot you are by a decent margin.”

Hozelock oscillating sprinkler

The Filter’s favourite misting fan: Shark FlexBreeze Pro Mist

If you’ve got access to a shaded, grassy area, playing under an oscillating sprinkler is a perennial summer favourite among Australian children – although it’s not acceptable during hosepipe bans. Adults may prefer an outdoor misting fan, which won’t get you as wet but will keep you cool.

Consider your dinner

If it’s already warm in your home, turning on the stove or oven will only make things worse. Try a no-cook summer meal, make dinner in a benchtop electric cooker or just use the microwave.

Cool your sleep down

Piglet in Bed Kemptown stripe linen-blend bedding

Make sure your bed is dressed in natural fibres, and don’t use poly-stuffed duvets. They may do a brilliant job of keeping you warm in winter, but in summer it will feel like you’re sleeping in a rubbish bag. After much sweaty trial and error, mulberry silk is the coolest duvet filling I’ve found, but when it’s particularly hot, a flat sheet is enough.

For bedding, I prefer linen sheets, but that preference is mostly aesthetic. Cotton is equally cool, and less costly: Piglet in Bed’s sheets were highly rated in our interiors experts’ guide to bedding. In my experience, bamboo and lyocell sheets feel cool at first, but aren’t very breathable, no matter what it says on their labels.

To bring your temperature down just before bed, take a cool shower. The cold water will lower your skin and core temperature and if you stay slightly damp, you’ll also benefit from the extra evaporation as you air dry.

There’s no harm in leaving fans on either, says Jay. “We’re testing fan use overnight during sleep in simulated hot tropical nights, so 35C with high humidity,” Jay says. “And the initial indication is they do seem to potentially improve sleep.”

Restructure your day

When hot weather is on the horizon, try to restructure your schedule to avoid strenuous activities during the hottest parts of the day. This should be enough to keep you safe from heat strain when temperatures are below 35C (the point at which heat becomes more dangerous for at-risk groups).

However, heat hits some people harder than others. Children under five and people over 65 have higher health risks. If you’re pregnant, have a disability or a chronic illness, be cautious. Seek support ahead of time if you know you’re vulnerable; and if you know someone vulnerable, offer to check in.

Temperatures over 40C are dangerous for everyone. In Australia, many local councils now have designated heat shelters for these conditions. In the absence of official facilities in your area, make a plan for where to go if your home becomes too hot. Air-conditioned public spaces like shopping centres and cinemas work well as ad-hoc climate refuges, as do local lidos.

If you can work from an air-conditioned office, a sweaty commute is usually worth the all-day comfort. Meanwhile, if you work outdoors, remember that heat is classed as a hazard, and your employer is legally obliged to protect you.

A word on air conditioning

If it’s regularly hotter than 28C inside your home, even with the blinds drawn during the day and the windows open at night, consider air conditioning. Walker, from the University of Sheffield, says that in the UK, “there is a kind of perception that [air conditioning] is a huge, energy-hungry system”, but “looking at the numbers, it isn’t as terrible as maybe we think”.

Air-to-air heat pumps use much less power than traditional forms of air conditioning, but can be costly and complicated to install, as the compressor needs to sit outdoors for the system to work, which typically requires structural alterations to a home. Newer Australian homes tend to have built-in ducted air conditioning, though wall-mounted air-to-air heat pump units are commonly retrofitted for older homes. Mitsubishi’s are well-regarded, and get top marks from Australia’s consumer watchdog, Choice.

The Filter’s favourite evaporative cooler: Swan Nordic 2-in-1

Evaporative coolers are one of the most affordable and energy-efficient ways to cool a room. Rather than extracting moisture from the air to cool your room down by multiple degrees, evaporative coolers use water to cool the air they blow towards you – like a sea breeze taking the edge off summer heat – and they use a fraction of the electricity of air conditioning. In our test of the best air coolers, Swan Nordic’s cooler was rated the best overall. They require dry air to function, and must be used with open windows in order to avoid mould. If your house is already damp or muggy, an evaporative cooler won’t help.

Portable air conditioners are not energy efficient, tend to be noisy and do not work as well as heat pumps. But for renters in homes too damp for evaporative coolers, and homeowners who can’t afford the initial install cost of an air-to-air heat pump, they are an effective last resort.

For more ways to keep cool, read our pick of the best fans and the best air coolers