Britain’s longest heatwave since 1976 has led to a upsurge in sleeping problems, with people left tired, irritable and less productive at work after sweaty nights of poor-quality shuteye.

Record temperatures of up to 32.4C (90.3F) have been stopping many people getting a proper rest as they struggle to get to sleep in rooms that are uncomfortably warm, experts say.

“I’m very aware of people reporting more difficulties sleeping as the temperature increases, both personally and professionally,” said Dr Michael Farquhar, a consultant in sleep medicine at the Evelina Children’s Hospital in London.

“It’s a phenomenon we’re becoming used to as we have yet another London summer where bedroom temperatures are regularly sitting at 30C.

“It’s a factor commonly cited in our clinics as a reason why children’s sleep patterns can worsen over the summer months.”

Over the weekend a further spell of unusually hot weather is due to replace the cooler weather of the last few days in many parts of the country, making a renewed spike in sleeplessness likely.

“Between 30% and 50% of the patients I have spoken to recently have talked about having sleep issues related to the heat,” said Dr Neil Stanley, an independent sleep expert and former director of sleep research at the University of Surrey.

“People can have their sleep massively impacted. Also at this time of year it doesn’t get dark until about 9pm or 10pm but when we go to bed it is still hot and sticky and the sun comes up earlier too, which means our sleep is disturbed.”

Stanley and Farquhar blamed the heatwave-induced sleep deprivation on the fact that so few homes in Britain have air conditioning compared to many European countries that are usually hotter.

“Britain isn’t really designed to deal with higher than average temperatures,” said Farquhar.

“Unlike warmer climates our homes are designed to keep us warm in winter more than to keep us cool in summer, and air conditioning is relatively rare in private homes. As a result bedroom temperatures rise to uncomfortable levels during sustained heatwaves.

“Temperature is a powerful influencing factor on our sleep. We have a relatively narrow range of temperatures in which we sleep comfortably – 16C to 18C is the usual optimum comfort zone – and either too hot or too cold leads to poorer sleep.”

The main problem, he added, is that the unusually high temperatures seen in all corners of the UK during recent weeks have left people unable to cool their homes down before bedtime.

“When the bedroom temperature is hot it prevents natural cooling,” he said, “which makes getting to sleep harder. When it’s humid it’s even harder as the humidity makes it harder to lose heat from our bodies by sweat evaporation. And when we do get to sleep, the sleep tends to be more fitful and restless, particularly in the early part of sleep, with more periods of wake.”

The result, Farquhar said, is that “with less sleep overnight we are more tired the next day, but also more irritable, more short-tempered, less likely to detect sarcasm, slower, more sluggish, with poorer reaction times and impaired judgment. In short, we become less nice people who don’t function as well.

“Scaled up to the whole country, a restless night’s sleep caused by high overnight temperature can potentially have a big cumulative impact on national productivity and effectiveness.”

Prof Helen Stokes-Lampard, chair of the Royal College of GPs, said: “Ideally a bedroom should be between 18C and 24C to enable restful sleep, so it’s not surprising that many people struggle during periods of extremely warmer weather, especially in countries like the UK where we’re not used to it.”

She advised those experiencing poor sleep during the heatwave to install a tall, rotating fan near their bed or sleep under thin cotton sheets in order to get cool enough to recharge their batteries properly overnight.

Eating a light dinner earlier in the evening than usual and restricting alcohol intake to a minimum are other useful ways to maximise the chances of a decent sleep, as the body then has fewer calories to burn off overnight, she added.

Having a cool shower or glass of iced water or spraying cool water on your skin just before bedtime can help make it easier to get to sleep, Farquhar said. Putting bedding, especially pillow cases, in the freezer for a while, will produce a cool surface that is easier to sleep on, he added.

He also recommended wearing cotton pyjamas and using cotton bedding, as they help draw sweat away from the body; keeping bedroom curtains shut during the day; leaving windows open and using earplugs to counteract any noise that results; and – perhaps the most difficult suggestion – sleeping alone.

“In the long run, I’d invest in air conditioning,” he said. “Hot summers are here to stay, I think.”