After what seems like the longest winter ever (was anyone else still wearing their coat in May?), summer has finally arrived, with temperatures soaring over the past month. 

And while we are big fans of summer, there’s one aspect of the warmer weather that isn’t much fun: how sleepy and lethargic it makes us feel.

When the mercury rises, it can be tough to motivate ourselves to do much at all. Exercise regimes fall by the wayside (who wants to do a HIIT in a heatwave?) and by the end of a workday, all we’re good for is a sundowner and snacks with mates. 

Unfortunately, life doesn’t come to a halt between June and August, and struggling with energy levels can make it really hard to maximise everything summer has to offer.

So, what is it about the heat that leaves us feeling so tired? Let’s explore.

Our bodies like a stable core temperature 

One of the many reasons that summer heat can feel so draining is that our bodies are working harder on the inside to maintain a stable temperature, allowing our internal organs to function properly. 

This constant internal environment is known as homeostasis – and it’s something our bodies are constantly trying to keep stable. 

“The body works hard to regulate its core temperature,” explains personal trainer Beth Davies. “In more extreme conditions – for example, a hot day – it takes more energy to maintain a consistent body temperature, which is why you may feel more sluggish or have less energy when it’s hot.”

We don’t sleep as well during a heatwave 

It’ll come as news to precisely nobody that it can be almost impossible to get a good night’s sleep when your bedroom feels like a roasting tin.

“Body temperature plays a crucial role in regulating our sleep patterns,” says chartered psychologist Dr Louise Goddard-Crawley. “Because temperature fluctuations can impact the quality and duration of our sleep, they indirectly influence our energy, mood and cognitive functioning during the day.”

When body temperature is too high, it can disrupt sleep and lead to difficulties falling asleep or maintaining a deep sleep state, leading to reduced sleep quality and daytime drowsiness – so try to keep your bedroom as cool as possible for a peaceful slumber. 

We’re out of routine

Human beings are creatures of habit, and even the smallest change to our routines can throw us off balance, particularly those of us who are sensitive to change. 

Hot and cold temperatures can make highly sensitive people feel grumpy, lethargic and generally out of sorts, so it can be helpful to try to create a daily schedule and stick to it. 

We’re a bit dehydrated

According to the NHS, feeling tired is a classic symptom of dehydration. We all know we should be upping our fluid intake when the weather is hot, but when temperatures really soar it can be tricky to take on enough fluid.

Even mild dehydration can cause issues – studies show that we can be dehydrated when we lose just 2% of our total body weight due to water depletion – and you might notice that you’re feeling irritable, lethargic and unable to concentrate. 

The good news is that mild dehydration can be quickly resolved. Make sure you’re topping up that water bottle regularly and eating plenty of hydrating, juicy fruits and vegetables such as watermelon, strawberries and cucumber, and you should feel better in no time.

If your symptoms persist, you could be at risk of developing heat exhaustion or heat stroke – a potentially serious health concern and medical emergency. If in doubt, seek medical attention. 

We’re in a sunshine state of mind 

Bees are buzzing, lawnmowers are whirring and the scent of summer is in the air. High temperatures don’t just impact our physiology, they also have an effect on our minds.

“Of the many aspects of weather, sunshine is the most intimately tied to mood,” Nick Haslam, professor of psychology at the University of Melbourne, says in The Conversation. “Anything that alters our moods can affect our behaviour.”

“Sunny days can invoke a relaxed, vacation-like mindset,” agrees entrepreneur and business mentor Shirley Palmer. “This mental state can encourage us to slow down and unwind, potentially contributing to the sensation of lethargy.” This can then become a vicious cycle: the less you do, the less you feel like doing. 

It can be difficult to focus on work when the weather is balmy and we’re all just waiting for 5pm to roll around. This can manifest itself as a lack of motivation (aka the summer slump), causing us to feel we’re not achieving much. 

If this sounds like you, try breaking your day into smaller, more achievable chunks to help boost productivity and improve your mindset. You’ll be out of that slump in no time.

Images: Getty