How to stay cool without air con – and help take some heat off the planet
“I can honestly say it’s the best thing I’ve ever spent my money on,” says 30-year-old Stephen about the unassuming waist-high plastic pillar that sits in the bedroom of his converted bungalow in Nottinghamshire. The retail worker has always found the room uncomfortably hot in summer, and his attempts to cool down using freestanding fans, electric air coolers and reading up on rudimentary fluid dynamics never seemed to cut it.
When peak temperatures began creeping towards the 40C (104F) mark a few years ago, he splashed out on a portable air conditioner and has never looked back. “If it were to break, I would immediately buy another without a second thought,” he says. “I don’t think I could cope without it in summer now.”
He won’t be the last to feel that way. Less than 5% of British homes were estimated to have air conditioning in 2021, with many of us relying on electric fans to make it through unusually sweaty days and sleepless nights. But as the planet’s global temperature continues to speed towards 1.5C warming, record-breaking heatwaves such as the one that pushed temperatures above 40C last year in the UK will become all the more regular. And with it, our demand to keep cool.
A study led by scientists at Oxford University’s Future of Cooling research programme warned last month that the UK will face a 30% jump in the number of uncomfortably hot days if the global temperature rise reaches 2C. While traditionally hot countries will experience the highest total need for cooling, the UK, Switzerland and Norway will suffer the most dramatic relative increase.
“When we talk about extreme temperatures, African countries are rightfully named as the most affected,” says Nicole Miranda, senior researcher on the Future of Cooling programme and joint first author of the study. “But this is the first study of its nature to show that northern countries are also going to be affected by heat.”
Yet British infrastructure and homes are almost uniquely unprepared. “The UK has some of the poorest housing stock in Europe when it comes to energy efficiency, largely due to poor levels of insulation,” says Abigail Ward, policy and communication officer at the Energy Saving Trust, an independent organisation working to address the climate crisis. She adds that British homes in winter lose heat on average three times faster than European houses. “Because home insulation works in a similar way to a thermal flask – keeping heat out in the summer and in during winter – the lack of sufficient insulation means UK homes are also illequipped to stay cool in hotter temperatures.”
For people such as Stephen who are already suffering from the discomfort of their warm homes, a portable air con unit that requires little in the way of installation can seem like an easy fix. But with much of the UK’s electricity still produced through burning fossil fuels, they do little more than cool our homes at the cost of warming our planet.
The Energy Saving Trust estimates an average portable air con unit used for eight hours a day during summer will produce about 140kg of CO2, the same as a seat on a flight from Belfast to Paris and 14 times that emitted by an average electric fan for the same duration. And as Miranda points out, the vicious cycle between air conditioning and greenhouse gases is already in motion, with National Grid resorting to firing up coal-fired power stations in June to meet the extra electricity demand from air con units.
Worse, they tend to leak highly polluting refrigerants – chemicals that are vital to their function but also double as particularly potent greenhouse gases. R-410A, one of the more common refrigerants used in commercial and retail air conditioners, has more than 2,000 times the global heating potential of carbon dioxide. While international agreements have gone some way to reduce their prevalence, they’re still common, and researchers hope those seeking to cool down during extreme temperatures will find other, more climate-friendly solutions.
A passive approach
Ollie Jay, a professor of heat and health at the University of Sydney, has spent years studying low-resource cooling strategies. By placing participants in climate chambers – sealed rooms where the environmental parameters can be precisely controlled – and monitoring their core temperatures under heatwave-simulating conditions, he has found that many of the most effective solutions are those that cool the individual rather than the surrounding air. Handily, they also don’t suck up great amounts of electricity.
Immersing your feet in cold water can reduce heat strain in both hot and humid conditions, while wearing wet clothing that’s resoaked every hour encourages cooling through evaporation. Drinking cold water is a less cumbersome and more direct way to provide internal cooling, and dousing yourself with water using a wet sponge or spray bottle, before allowing the water to evaporate from the skin, is one of the most effective, albeit less commonly advocated, solutions. Though many of these strategies will seem rudimentary and obvious to some, Jay suggests it pays to be judicious.
“So much of what people are advised, even by public health agencies, is informed by conventional wisdom and old wives’ tales,” he says. “It’s essential that we ensure that the actions we are advising people to take have a scientific basis, that they are actually effective at reducing the physiological heat strain that develops when exposed to the heat, because this is what is ultimately dangerous.”
Circulating air using an electric fan, for instance, is a simple way of accelerating the rate at which sweat evaporates from your skin. But try directing one at yourself in temperatures above 42C and you’ll find you quickly overheat. When the air temperature vastly exceeds that of your skin, electric fans do little more than replicate a convection oven: circulating hot air that your body will absorb faster than if you were sitting in a still room. It’s uncomfortable and makes any evaporative benefits obsolete.
“The other thing worth considering is that strategies that make you feel cool may not actually be effectively reducing the internal physiological heat strain all that much,” says Jay. “Thermal sensation is influenced by thermoreceptors on the skin and it’s possible to cool the skin without it necessarily having all that much influence on the deeper tissues of the body.”
Thirst is a typical case. The sensation usually develops well after the body starts to become dehydrated, so relying solely on your own physiological signals to remind you when to drink during a heatwave often isn’t enough. “How we feel, while of course important, isn’t necessarily the most reliable indicator of how much strain
the body is under when exposed to heat,” Jay says.
One of the great challenges of cooling is not only reactively responding to oppressive temperatures but adequately preparing for them. Much of this is done through the design of homes to promote passive cooling. Houses in the Middle East have long been constructed with built-in towers called windcatchers that capture cool air and recirculate it throughout the home, and light-coloured paint has proved effective for reflecting heat from the roofs of houses in Pakistan. In the UK, less architecturally involved add-ons can be easily retrofitted to the abundance of older homes that were built to withstand our traditionally colder climate.
Shading is essential. Closing blinds and shutters, opening awnings and hanging blackout curtains on the sunfacing side of your home can block its heating effects. Although basic, it’s effective, and researchers in Spain have found external window shutters can reduce the energy required (such as for air cons or electric fans) to keep people comfortable by up to 14%. For those with gardens, vegetation offers a passive cooling solution. In summer, tall deciduous trees and window shrubs provide essential shade, before shedding their leaves in the colder months to allow the sun to pass through and reach interiors.
Ventilation is also important. Opening windows in the evening allows cooler air to enter and warm air to escape. It’s most effective when cross ventilation can be achieved, whereby cool air moves through an area from one side to the other, maximising circulation.
“We’ve had cheap fossil fuels for so long, and not that many extreme temperatures, we’ve forgotten how to do a lot of the really basic stuff,” says Aaron Gillich, a professor of building decarbonisation at London South Bank University. “Every single home in the country needs to think about them, and there will be a surprising number of fixes that are really achievable at reasonable cost.”
Part of the solution
Since its invention in the early 20th century, modern air conditioning has had a transformative effect on much of the world. No longer restricted by the natural heating cycle of the sun, those in hot climates have been free to work and play in otherwise oppressive temperatures. China’s industrialisation is all but reliant on it, with the country accounting for about one-third of the world’s installed air cons. Singapore’s founding prime minister, Lee Kuan Yew, called it “perhaps one of the signal inventions of history” and attributed the success of his country to its innovation.
Although air conditioning’s impact on the UK has been more muted, Miranda points out that it continues to provide essential comfort to the elderly, infants and other vulnerable members of society. That’s unlikely to change, she says, but it’s important to recognise the technology’s value while also prioritising proper ventilation, insulation, light levels, and seasonal demands in the construction and design of new buildings. “There’s so many passive measures that can be implemented that will save our energy bills and save emissions,” she says. “So air conditioning can be part of the solution, but not the go-to.”
Yet even the most tried-and-tested passive cooling techniques may prove insufficient amid changing climate conditions. Shaded indoor environments are enough to get us through hot days only so long as we can properly cool off when the sun goes down, and ventilation systems similarly require the outside air temperature to drop before it can be invited in. But as heatwaves last longer and temperatures stay high well into the night, the climate patterns on which these centuries-old cooling practices rely are already beginning to break down.
“We will hit a wall sometime in the next decade or two where the past techniques are just not fit for purpose any more,” says Gillich. “A lot of buildings are just going to need air conditioning no matter what, or they will be completely unlivable.”
The white plastic box in Stephen’s bedroom, then, may become a familiar sight in all our homes. The question remains just how much we’ll rely on it.
• This article was amended on Sunday 27 August to correct a description of the Energy Saving Trust’s estimate of CO2 production from use of an air con unit.
We will hit a wall sometime in the next decade or two where the past cooling techniques are not fit for purpose any more
Aaron Gillich, professor of building decarbonisation
determined to get better, but in the end was left on the ward so long she sensed she was going to die.
The first months after her death was a time of shock, zombie numbness, constant flashbacks, very little sleep. I would have welcomed a nuclear apocalypse. The world seemed offensively crammed with people less deserving of life than Martha.
Because bereaved parents feel so shipwrecked and alone, they often seek each other out. We did within weeks. Group meetings of people who’ve lost kids are extraordinary experiences, intense and exhausting. Each story – of cancer, say, or suicide – capsizes you. People from all areas of life are there, but everyone has hit the limits of emotional endurance. It’s inscribed in their faces. You feel a desperate solidarity: they know.
After Martha disappeared so suddenly, I still had a compulsion to care for her – it was a 14-year habit. I felt the urgent need to “fight for her”, driven in part by my sense that I had failed to fight for her during her final days. One of the only ways in which I was able to do something for her was to find out all I could about how she was allowed to die.
So Merope and I began to send emails to King’s, requesting documents and asking questions. We were consulted as part of investigations and had a number of meetings, but some requests were denied, and it was an uphill struggle. It was only because we kept pressing that important details about
Martha’s case were discovered.
In the weeks after Merope wrote her article, which was widely read, she received an extraordinary number of responses from doctors, full of sympathy and concern. One GP put a picture of Martha on the wall of her surgery, as a reminder to listen to patients and those at their bedside. Dozens of medics expressed astonishment at what happened, but recognised the problems of arrogance and hierarchy in hospitals. Martha’s story, we were told, would be taught in medical schools: it could be used to prevent future deaths.
But we found a different attitude on the social media site Reddit, as part of a thread in which junior doctors talked among themselves, with anonymity, about Merope’s piece. The “us” and “them” attitude, while perhaps inevitable, was striking: many posts were compassionate, but others assumed that a layperson like Merope couldn’t possibly understand the situation, even suggesting she wasn’t telling the truth.
When the question of parents insisting on intensive care was raised, one comment was: “Thing is, I highly doubt most members of the public would be able to articulate on that level.” Another post read: “Patients’ degree of entitlement/inability to accept mistakes is just simply unsustainable, wholly incorrect and an enormous burden.” Merope was castigated as yet another relative who couldn’t control her emotions – “Grief isn’t an excuse to act out… pathetic.” It was “Sad for the parent, but beyond that people die and that’s life.”
Since then, an independent report – commissioned by King’s College Hospital – found there was “a departmental and Trust responsibility” for Martha’s death. We learned shocking new details, which the most senior figures at King’s found uncomfortable. Talking to us, the consultants who wrote the report used words like “horrific” and “indefensible”. They found a “litany of failures”. They also made clear the extent to which a doctor at the heart of the case had refused to accept her obvious errors (“We are both a little stunned”). Even more depressing was their reflection that only one of the many doctors they interviewed “spoke about Martha as a person”.
After two years, I’m able to function, but remain in denial. Looking at photos of Martha, it seems untenable that she’s not around. My mind constantly shuttles back and forth between our life now and the one we “should” be – she should be – living. And there’s the fantasy bargaining: of course I’d instantly give up my life in exchange for her just going through sixth form, or to university.
How has Martha’s death changed my view of the world? I feel more viscerally aligned with those who feel that the “system” or state doesn’t work in their interests. I’m more cynical than ever about how large institutions are run – protecting the brand by giving evasive, anodyne responses matters more than admitting the whole truth. I’m fed up with lazy uses of the word “trauma” – and more drawn to people who’ve genuinely suffered it. And I no longer have any fear of death (compared to Martha, I’ve had such a long life).
By now, people seem to expect a “coming to terms”; I should be making my way back and be trusted not to let untidy feelings break the surface of civility. Some tears are allowed, but not anger, which is off-putting, corrosive – even tiresome. Writing this kind of article, I feel another weight of expectation: that I have some kind of positive narrative or advice to give. This is how I pulled through! Here’s my new perspective on how to live! Lose yourself in nature, take up a craft, try ayahuasca, go cold-water swimming, find God… I’m willing to believe all might help.
I do think I understand better what I’m trying to achieve in my “grief work”. I need to nurture the feeling of having been lucky to spend 14 years with Martha – a sense of positivity that can sit alongside the pain. I have to resist the pull of nostalgia. I can feel delighted that a writing prize has been set up in her name. Above all, I’m so lucky to have her wonderful sister.
For the moment, though, everything is still too ragged and raw; it seems wrong to push aside the unpalatable truths about how Martha died. I simply can’t forgive myself for my passivity. And I miss her so much.
Martha’s bedroom remains as it was the day she died, though Lottie has rearranged her desk with some favourite things. The room has become a reliquary of sorts, with mundane objects taking on a heightened meaning – daft selfies of her and her friends; fragments of stories, plays and song lyrics she was writing; drawers left open with her jeans and hoodies spilling out.
I believed the doctors when they said Martha would soon ‘turn a corner’
There’s a linein a Nick Laird poem: “Impossible to grieve/and not know the vanity of grief.” Whatever we are going through, the thing that matters most is that Martha didn’t get to live. I see groups of girls coming to and from school, and imagine her among them, chatting about parties and playlists or scrolling TikTok. I think of the moments, lovely and quotidian, captured by one of her friends, from the weeks before she died:
“One of us brought hot chocolate in a flask and we couldn’t stop laughing because we were sipping the chocolate so slowly and we thought we looked like old grannies enjoying the train view with their tea.
“On the last day of Year 8 we had a water fight. Our friends had gone to fill up the water guns and me and Martha talked about the boys that we liked, though they had no idea we liked them.”
Just ordinary days and the promise of experience. Her friends are now older, taller, embracing a new phase. But Martha never got to start Year 9. And she had so many plans...