Usually when the sun shines in Britain it’s a scramble to fire up the barbecue and mainline Pimm’s, knowing this rare gift won’t last long. This summer’s heatwave, however, has made us think differently.

Us Brits might long for warm weather, but the truth is we don’t know what to do with 33 degrees unless we’re poolside with a margarita. This heat is making us sluggish, sleep-starved, irritable and slightly unhinged, and as there’s no sign of it abating any time soon, all we can do is try to understand why.

Getting heated 

Recent research from Poland’s Poznan University suggests hot weather might be, in itself, more stressful than cool. It found that levels of the stress hormone cortisol spike during the summer, making us more likely to get annoyed by things we’d probably ignore on a cloudy day in March.

Neuroscientist Dr Dean Burnett agrees. “Heat is harder to block out than cold weather. You can lose the sense that you’re in control of your life, making you feel on edge and irritable,” he says. “Raised temperatures also increase heart rate and testosterone levels, which trigger the sympathetic nervous system. This makes your brain more primed for a fight or flight response, and often people choose fight.”

This explains why you might experience more aggression in public than normal, especially in a city surrounded by sticky bodies all trying to get somewhere fast. In July, temperatures of 37.5 degrees were recorded on a Southeastern train – to put that in context, EU legislation specifies that cattle can’t be transported at temperatures higher than 30 degrees. 

Sophia, 29, is originally from Spain but now lives in London. “It’s so hot on the Tube it’s actually hard to breathe, so everyone is literally at boiling point. I’ve seen full-on shouting matches at 8am.” Lack of rest when it’s #TooHotToSleep is also fuelling our short tempers. In a recent study, almost two thirds of people reported difficulty sleeping in the hot weather. Presumably the other third were too tired to answer.

Sleep expert Dr Neil Stanley, author of How To Sleep Well, says it’s all down to something called thermoregulation. “To get a good night’s sleep, you need to lose around one degree of body temperature, and these warm nights mean that’s not easy,” he says. “Our homes simply aren’t designed for high temperatures. Unlike Spanish or Greek houses which are white to reflect heat, ours are dark, with large windows that let in sunlight, and we’re often crammed in next to neighbours.”

Some like it hot (others don’t)

The close proximity of a partner can make it even harder to keep your cool on muggy nights. Dr Stanley says that depleted levels of patience can mean romantic relationships feel the strain when you’re desperately seeking shut-eye. Screaming “WHY ARE YOU TOUCHING ME?” or “TURN THE FAN TOWARDS ME” at 3am can mean separate beds – and separate fans – feel like the only solution for retaining some sanity.

Dr Stanley’s clients include couples sleeping separately due to the weather, and he says most are having a period of unplanned celibacy as “the idea of getting any hotter is unthinkable”. The heatwave causing a lack of sex is supported by the National Bureau of Economic Research’s recent study, which revealed that babies are not likely to be conceived on the hottest days of the year because the heat makes us reluctant to do anything physically exerting, especially if it involves another sweaty body.

Victoria, 31, from Leeds, and her husband Tom have been taking turns to sleep on the sofa since the beginning of July. “We play a never-ending game of ‘who is the most tired?’, have little physical contact and argue more than ever. I feel ungrateful as we usually long for good weather, but I just want it to end,” she says.

That’s not to say no one is having heatwave romances. Stripping off in sun-soaked parks can inspire a reckless holiday mood, and there are many theories around why sunny weather can make you feel friskier.

A paper published in the journal Psychological Science found that people associate warmth with intimacy. Dr Anita Patel says sunlight has been shown to have an association with serotonin, a key neurotransmitter in the ability to experience pleasure.

Absorbing some vitamin D from the sun’s rays can also increase women’s levels of oestrogen, meaning both your hormones and your libido might well peak during the sunny weather.

And while stepping off a bus covered in sweat may not exactly scream sexy, scientists believe that in increased heat we excrete pheromones, the airborne chemicals related to attraction.

Taking its toll 

One much less attractive by-product of perspiration is the heatwave phenomenon known as ‘sweaty underboob’. Social media groans under the weight of women sharing tips on how to cope with it and bemoaning having to wash bras at twice the usual rate. 

Perhaps the oddest solution yet was thought up by Erin Robertson in Los Angeles. Called the Ta-Ta Towel, its a piece of towelling that slings over your neck and holds up your boobs to absorb sweat. A Ta-Ta Towel spokesperson says they’ve seen a 29% increase in orders from the UK since June.

And as the mercury continues to soar, so does the likelihood of ill effects. In homes and offices that don’t have air con, or for anyone who works outside, there’s a real risk of overheating. Dr Jessica Butler says a heatwave puts stress on our bodies that can cause dizziness, fainting, heat stroke or even heat cramps.

Dr Butler adds that “one of the main concerns is the effect the hot weather has on city pollution”. As the heatwave took hold last month, London mayor Sadiq Khan issued a toxic air warning. This is caused by the heat and sunlight essentially cooking the chemical compounds in the air. This ‘chemical soup’ combines with nitrogen oxide emissions, making breathing difficult for those who already have respiratory or heart problems. But it can also make healthy people more susceptible to respiratory infections, which might explain that annoying summer cough.

Even our beloved handheld fans, sales of which have increased by more than 1000% on Amazon, might be doing as much harm as good. By rapidly moving air they can dry out your nasal passage, leading to discomfort or nose bleeds, and they also circulate dust which can bother people who have allergies.

As a nation we are just not geared up for this weather. We are built for drizzle and grey skies. “In Britain we only ever have the wrong weather, first the Beast from the East and now this record-breaking hot summer,” says Dr Burnett. “Even though sunshine is usually seen as positive, such extreme and prolonged heat feels incompatible with the way we live. It means we can’t do what we want, so productivity goes down and we don’t feel like our usual selves, which can make us feel less happy. There can also be a feeling of ‘wasting’ the good weather if we’re not making the most of it, which can also affect mood.”

If some meteorologists are to be believed, extremely hot UK summers may be the new normal, meaning the ‘summertime blues’ could become a regular part of life. For many of us, 2018 will be burnt in the memory as one we endured rather than enjoyed.

Thankfully, it’s never too hot to have a moan.

Images: Getty / Unsplash