HOT WEATHER SURVIVAL GUIDE: HOW TO SLEEP AT NIGHT, CONCENTRATE DURING THE DAY AND STAY ENERGISED IN HIGH HUMIDITY
How to sleep
If you thought sleeping in a heatwave was bad, humidity ups the challenge yet further. The ideal level for decent sleep is between 30 and 50 per cent; anything higher can prevent sweating, which “is a way of cooling you down”, says Dr Neil Stanley, author of How to Sleep Well.
“If you don’t sweat, the moisture stays on the skin – which it does in humid climates. This switches the sweating response off, so you don’t lose temperature.”
That means many of the old heatwave tricks – such as putting a bowl of ice water in front of a fan to cool the breeze – won’t work. “The water from the bowl doesn’t evaporate; instead, it just contributes to the humidity,” says Dr Stanley.
Rather, we should be looking to air flow to try to regulate our body temperatures. If you have an attic in your house, Dr Stanley recommends propping open the hatch as this can act like a chimney. Also, sleeping downstairs could be a good option.
“Try to get a cross-draught, if you can,” he advises. “Open windows judiciously so there is a movement of air, which cools you down and wicks away the moisture from your body. If it’s too noisy outside, use a desk fan.”
And in tropical climates, the old wives’ tales of sleeping naked and taking a cold shower before bed shouldn’t be believed. Instead, Dr Stanley recommends wearing light bamboo or cotton pyjamas that can help absorb the moisture off your skin, and avoiding sheets and duvets, too.
“Cold showers actually cool down the skin, leading your body to produce more temperature, in order to pump some hot blood to the surface,” he says. “A warm shower tells your body: the outside is warm, I don’t need to produce any more heat.”
And what about those pesky thunderstorms? Unfortunately, there’s not a lot we can do, as lightning puts our body into fight or flight mode. “To sleep, your body needs to feel safe and secure,” says Dr Stanley.
“Something like a lightning flash can put your body into a heightened state of arousal. If you are asleep and there is a noise or a flash, you can perceive it. Your brain has to wake up and ask: what is that?”
Blackout blinds could be a good option here, as they reduce the “solar load” – that’s the light coming into your bedroom – while also keeping the window cool. A pink noise generator (less abrasive and static-sounding than its white equivalent) can help mask the annoyance of thunder by giving your brain something to passively listen to.
How to concentrate
Environmental psychologist Lee Chambers says that we lack concentration in hot weather because our bodies are having to adapt and work harder to regulate our temperature downwards. “We have a physiological response to bring that core body temperature down, and that response takes quite a bit of energy,” he says.
“The higher temperatures also affect our neuro transmitter production, slowing down our brain cells and affecting our cognitive performance.”
He adds that heat is an “environmental stressor”, which can leave us “feeling drained and our minds clouded”
Francesca Dal Corso, the co-founder of Superbrain, a training company that specialises in boosting mental effectiveness, advises that “breaking our work down into shorter deadlines, of around 25 minutes, can help us to retain concentration”; taking regular breaks will also allow your mind to rest and recover. “Even consider taking a nap, as is so often utilised in tropical climates,” Chambers says.
“Avoid any high intensity physical activity during the temperature peaks, but ensure you stay moving either side to keep cognitively active.”
How to maintain your energy levels
More humidity means more sweat, so drinking plenty of water is vital: studies show that just a two per cent loss of body weight due to dehydration can reduce cognitive performance. “When you get sweaty, you’re using electrolytes and energy, which can cause our concentration to dip,” says nutritionist Julie Silver ( juliesilver. co.uk).
And, before you reach for an ice cream, not so fast. “We need to replace the body’s natural electrolytes, that contain the minerals chloride, magnesium, potassium and sodium,” says Silver.