When temperatures rise, your body has to work harder to keep itself cool. This can lead to swollen hands and feet, muscle cramps, dehydration, headaches, fatigue and changes in how your muscles and joints feel. Hot weather can also affect exercise, sleep and your general wellbeing.

In NCTV Episode 129, Nick Coysh, osteopath at Nicholas Coysh Osteopathy & Wellbeing in Storrington, West Sussex, looks at how heatwaves affect the body and shares some simple ways to stay comfortable, hydrated and active when temperatures climb.

NCTV Episode 129: What does this video cover?

☀️ How hot weather affects your body
💧 Why dehydration can cause headaches and muscle cramps
🦶 Why your hands, feet and ankles can swell in the heat
🦴 How warm weather can affect muscles and joints
🏃 How to exercise safely during a heatwave
😴 Why hot weather can disrupt your sleep
🥤 Simple ways to stay hydrated and comfortable
🩺 How osteopathy may help with heat-related aches and stiffness

Why does hot weather affect your body?

Your body has to work harder in hot weather to maintain its normal internal temperature. One of the ways it does this is by widening blood vessels near the skin, allowing more heat to escape.

You also sweat more, which helps cool you down but means you lose fluid and, particularly during prolonged or heavy sweating, important electrolytes.

The result can be surprisingly noticeable. You might find your fingers feel swollen, your legs feel heavier, your muscles cramp more easily or you simply feel more tired than usual.

For many people, these effects are temporary and improve once they cool down and replace lost fluids. However, very hot weather can become more serious, particularly for older adults, people with certain long-term health conditions and anyone exercising or working outdoors.

Why do my hands, feet and ankles swell in hot weather?

If your rings suddenly feel tighter or your shoes seem to have mysteriously shrunk, the weather could be responsible!

Heat causes blood vessels to widen. This helps your body release heat but can also encourage more fluid to collect in the tissues, particularly around the hands, feet and ankles.

Heat-related swelling is often temporary.

Some simple things that may help include:

  • 💧 Keeping hydrated throughout the day
  • 🚶 Gentle movement such as walking
  • 🦶 Elevating your feet for a while
  • 🪑 Avoiding sitting or standing in one position for prolonged periods
  • ❄️ Moving somewhere cooler when possible

If swelling is severe, persistent, occurs suddenly or affects just one limb, it is worth getting medical advice rather than simply blaming the weather.

Can hot weather cause muscle cramps?

It can contribute to them.

When you’re sweating heavily, you lose water and electrolytes. If these aren’t adequately replaced, muscles can become more prone to cramping.

Calves, feet and hamstrings are common areas for cramps, particularly during exercise or physical activity.

This can catch people out during summer because activities that feel relatively easy in cooler weather can place considerably more demand on the body when temperatures are high.

Gardening, running, tennis, cycling and even mowing the lawn can all become more physically demanding in the heat.

Try drinking regularly rather than waiting until you’re extremely thirsty, and take appropriate breaks when exercising or working outdoors.

Does hot weather make arthritis better or worse?

There isn’t one universal answer.

Some people with arthritis find warmer weather makes them feel less stiff and more comfortable. Warmth can help muscles relax and may make movement feel easier.

Other people notice increased swelling or discomfort, particularly when temperatures are very high.

So if your joints appear to have their own relationship with the weather forecast, you’re certainly not alone!

The important thing is to pay attention to how your body responds rather than assuming that hot weather will automatically improve or worsen arthritis.

If you’re experiencing persistent joint pain, stiffness or swelling, an appropriate healthcare professional can help assess what’s going on.

Why do I get headaches and feel tired in hot weather?

Dehydration is one common contributor to headaches during hot weather.

When you’re sweating more, you need to replace the fluid you’re losing. If you don’t, you can start to feel tired, sluggish and generally below par.

Hot weather can also interfere with sleep. A bedroom that’s considerably warmer than usual can make it harder to fall asleep and may reduce sleep quality.

Put those two things together and it’s hardly surprising that you might feel more fatigued, irritable or less focused during a heatwave.

And if you’ve walked into a room and forgotten why you’re there, perhaps don’t blame your memory entirely. It might just be the sunshine!

Is it safe to exercise during a heatwave?

You can still be active during hot weather, but when and how you exercise matters.

If possible, exercise during the cooler parts of the day, such as early morning or later in the evening.

You can also:

  • 🏃 Reduce the intensity of your workout when temperatures are particularly high
  • 💧 Take water with you and drink regularly
  • 👕 Wear lightweight, breathable clothing
  • 🌳 Choose shaded routes where possible
  • ⏸️ Take more frequent breaks
  • 🛑 Stop if you begin feeling unwell

Remember, your body is already using energy to regulate its temperature. A run that feels perfectly manageable on a cool morning can feel considerably harder when the temperature rises.

Don’t be afraid to adjust your plans. Missing one hard session is considerably better than turning it into a medical emergency.

How can I sleep better during hot weather?

A hot bedroom can make a good night’s sleep surprisingly difficult.

Try to keep the room as cool as possible during the day by closing curtains or blinds when the sun is strongest. If temperatures fall in the evening, open windows to allow cooler air in.

Other simple strategies include:

  • 🛏️ Using lightweight bedding
  • 🚿 Having a cool shower before bed
  • 💧 Staying adequately hydrated
  • 🌡️ Keeping the bedroom as cool as practical
  • 🕰️ Maintaining your normal sleep routine

You don’t need to turn your bedroom into an Arctic research station, but a few degrees can make a noticeable difference.

What can I do to stay healthy during a heatwave?

The basics really do matter.

Drink regularly. Don’t wait until you’re desperately thirsty before reaching for the water.

Eat water-rich foods. Foods such as melon, cucumber and strawberries can contribute to your overall fluid intake.

Take breaks. If you’re gardening or working outdoors, build regular rests into your day and seek shade where possible.

Think about your footwear. Flip-flops are fine for a trip to the beach or around the pool, but supportive footwear is usually a better option if you’re walking or standing for long periods.

Protect your skin. Sunscreen isn’t directly related to your muscles and joints, but it is an essential part of looking after yourself in hot weather. You’ve only got one skin, after all!

Can osteopathy help with aches and pains during hot weather?

Hot weather itself doesn’t usually cause musculoskeletal injuries, but it can highlight aches, stiffness and niggles that were already developing.

For example, changes in activity levels, more walking, gardening, sport, travel and time outdoors can all put additional demands on your body.

Osteopathy may be able to help by looking at things such as:

  • Joint mobility
  • Muscle tension
  • Areas of stiffness
  • Movement patterns
  • Posture
  • Recovery following physical activity

Treatment can be combined with practical advice about exercise, movement and managing your activity levels.

The aim isn’t to treat the weather itself, unfortunately, even an osteopath can’t negotiate with the British summer, but to help your body move as comfortably and efficiently as possible.

What other things can help with heat-related aches and pains?

Osteopathy is just one option.

Depending on the problem, useful approaches may include:

  • Physiotherapy and rehabilitation
  • Appropriate strengthening exercises
  • Mobility work
  • Exercise modification
  • Rest and recovery
  • Advice from your GP or another healthcare professional when appropriate

The best approach depends on what’s actually causing the symptoms.

When should I seek medical help during a heatwave?

Most mild heat-related symptoms improve with cooling, rest and appropriate hydration.

However, heat-related illness can become serious.

Seek urgent medical help if someone becomes very unwell, particularly if they develop symptoms such as confusion, collapse, severe weakness, difficulty breathing or loss of consciousness.

Likewise, don’t automatically assume that significant swelling, severe pain or unusual symptoms are simply because it’s hot. If you’re concerned, seek appropriate medical advice.

How hot can it get in the UK?

You might associate extreme heat with countries much further south, but the UK can experience surprisingly high temperatures.

The UK’s highest recorded temperature was 40.3°C, recorded at Coningsby in Lincolnshire in July 2022.

That gives some perspective on just how much our summers have changed. Although a British summer in the high 20s might not sound extreme compared with temperatures elsewhere in the world, our bodies still need time to adapt, particularly when we’re exercising or working outdoors.

Common questions about heatwave health

Can hot weather make your feet swell?

Yes. Heat can cause blood vessels to widen and may contribute to temporary fluid accumulation around the feet and ankles.

Does dehydration cause muscle cramps?

Dehydration and loss of electrolytes during heavy sweating can contribute to muscle cramps, particularly during physical activity.

Why do I feel more tired when it’s hot?

Your body has to work harder to regulate its temperature. Dehydration and disrupted sleep can add to fatigue.

Should I exercise when it’s very hot?

You may still be able to exercise, but consider reducing intensity, exercising during cooler parts of the day, staying hydrated and taking more breaks. Stop if you feel unwell.

Can hot weather affect joint pain?

Yes, although the response varies between individuals. Some people feel less stiff in warmer weather, while others may experience more swelling or discomfort.

How can I stay cool at night?

Keep your bedroom as cool as practical, block strong sunlight during the day, ventilate when outdoor temperatures fall, use lightweight bedding and stay hydrated.

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About NCTV

NCTV – Nicholas Coysh TV is Nick Coysh’s regular series of bitesize health and wellbeing videos, covering common aches, pains, injuries, exercise, posture, mobility and general wellbeing.

Nick Coysh is an osteopath based in Storrington, West Sussex, helping people manage pain, improve mobility and understand how to look after their bodies through hands-on treatment and practical aftercare advice.

If you’re struggling with an ongoing ache or niggle, speak to Nick to discuss whether osteopathy may be appropriate for you.

This article is for general information and education and is not intended to replace individual medical advice, diagnosis or treatment. If you are concerned about your symptoms, please seek advice from an appropriately qualified healthcare professional.