Summer Exhaustion (Or ‘Natsubate’) Might Be The Reason You’re So Tired

Everyone – and I mean, everyone – I’ve spoken to this week has remarked on how tired they’ve felt.

I’ve felt it too. That level of bone-deep exhaustion that makes you feel like you could simply drop to the floor and drift off to sleep, even thought it’s 1pm.

And it turns out there’s a relatively simple explanation as to why there’s been this level of collective fatigue, especially in areas impacted by last week’s extreme heatwave.

In Japan – where the summers tend to be hot but also very humid (a bit like last week’s heatwave) – they call it ‘natsubate’, which Tokyo Weekender said translates as ‘summer exhaustion’.

The heatwave has had more of an impact on your body than you might think.

There are a few factors at play here. Dr Ginni Mansberg, a GP and co-founder of ESK, said our bodies work overtime when the weather’s super hot.

“Summer fatigue is a real phenomenon, although it’s not a formal medical diagnosis,” she told HuffPost UK.

“During a heatwave, your body has to work much harder to keep your core temperature in a safe range. That means diverting blood to the skin, increasing sweating and making your heart work a little harder.”

All of that uses energy, which can result in that tired, sluggish feeling. On top of that, you’re also sweating a lot to cool yourself down, which results in water and electrolytes being lost in the process.

“Even mild dehydration can leave you feeling tired, foggy and less able to concentrate,” added the expert.

“Add a few nights of poor sleep because it’s too hot, and it’s no surprise you’re running on empty.”

There’s also another factor that’s often overlooked, but will play a crucial part in tiredness levels.

Dr Asiya Maula, private GP at The Health Suite, highlighted that we tend to change our routines during a heatwave: “We often spend more time outdoors, walk more, travel more, exercise in warmer conditions or drink more alcohol at barbecues and social events.

“All of those place additional demands on the body and can contribute to that lingering feeling of fatigue.”

So, after a full week of disrupted sleep, dehydration, your body working overtime and shifted routines (potentially with a hefty dose of sunshine-fuelled socialising and booze), it’s going to take your body some time to feel refreshed again. And this is where your current ‘heatwave hangover’ comes in.

Dr Maula said: “Many people notice they feel unusually tired after a spell of very hot weather, even once temperatures have started to cool down. It’s sometimes referred to as a ‘heatwave hangover’, and it’s a very real response to the extra strain heat places on the body.”

Even people who have been mildly dehydrated can feel drained for several days afterwards, she added.

Recovery is usually straightforward. “The best approach is to continue drinking fluids regularly over the days that follow, eat balanced meals, replace electrolytes if you’ve been sweating heavily, and prioritise good-quality sleep,” said Dr Maula.

“Gentle movement, rather than intense exercise, can also help people feel more energised as they recover.”

With another bout of hot weather predicted for London this weekend and running into next week, it’s important to stay well hydrated, stick to early morning or later exercise sessions, and keep your home cool by shutting curtains and windows during the day.

And if your extreme tiredness doesn’t improve after a couple of weeks, becomes progressively worse, or is accompanied by symptoms such as chest pain, severe breathlessness, unexplained weight loss or persistent fevers, it’s important to seek medical advice, added Dr Maula, as fatigue can have many different causes beyond hot weather.