Quick answer: In a heatwave, keep cool by staying out of the sun between 11am and 3pm, closing curtains during the day and drinking plenty of fluids. Use cold packs on swollen joints, move gently in the cooler morning or evening, and ask a pharmacist whether your medicines affect heat tolerance. Get help quickly for signs of heat exhaustion.
Summer usually brings longer days and an easier time for stiff joints. But UK heatwaves are becoming more common, and very hot weather can be tough when you have arthritis. Some people find their joints swell or ache more, tiredness gets worse, sleep suffers and medicines need extra thought. This guide explains how to stay comfortable and safe when temperatures rise, with practical steps based on NHS heatwave advice.
How heat can affect arthritis
People react differently. Many feel looser and less stiff in warm weather. Others, including some people with inflammatory arthritis, notice more swelling, aching and fatigue when it is hot and humid. Research on weather and arthritis pain is mixed; our guide to weather and arthritis pain explains what is known. Common effects in a heatwave include:
- Swelling: heat can make hands, ankles and feet puffier, which can make joints feel tight.
- Tiredness: heat is draining, and arthritis fatigue can feel worse.
- Poor sleep: hot nights make it hard to settle, and poor sleep makes pain harder to cope with.
- Dehydration: which can cause dizziness and tiredness, and in gout is one of the known triggers for an attack, according to the NHS.
- Less activity: it is tempting to sit still all day, which can lead to stiffness.
Who needs to take extra care
The NHS lists groups more at risk in hot weather. Several apply to many people with arthritis:
- Older people, especially those over 75
- People with long-term conditions, including heart, breathing or kidney problems, diabetes and mobility problems
- People who live alone and may be unable to look after themselves
- People on multiple medicines, or medicines that may make them more affected by hot weather
- People who are already unwell and dehydrated
If this is you, or someone you care for, plan ahead for hot spells. Our guide to heatwaves, arthritis and frailty has extra advice for older adults and carers.
Keep cool: NHS heatwave basics
The NHS advice for coping in hot weather is:
- Keep out of the heat if you can. If you go out, stay in the shade, especially between 11am and 3pm, and wear sunscreen, a hat and light clothes.
- Avoid exercise or activity that makes you hotter during the hottest part of the day.
- Cool yourself down: have cold food and regular cold drinks, and have a cool shower or put cool water on your skin or clothes.
- Drink extra fluids, but avoid alcohol, caffeine and hot drinks.
- Keep your living space cool: close windows, curtains and blinds during the day and open them at night when it is cooler outside.
- Check on others who may be at risk, such as older neighbours or relatives.
Practical tips if your hands or mobility are affected
- Fill a large, light jug of water each morning so you are not lifting heavy bottles all day. A jug with a big handle is easier on painful hands.
- Use a bottle with a sports cap or a cup with a straw if gripping or lifting is difficult.
- Keep a cool damp flannel or a spray bottle of water within reach.
- A small fan by your chair or bed helps air move. Fans are less effective once the air is very hot, so use them with other cooling steps.
- Choose loose, light-coloured cotton clothes that are easy to get on and off.
- Ask someone to help close curtains and open windows if reaching is difficult.
Managing swollen, hot joints in the heat
- Cold packs: a cold pack or bag of frozen peas wrapped in a tea towel for 10 to 15 minutes can ease swollen, warm joints. Never put ice directly on the skin. See our guide to heat versus ice.
- Raise swollen legs and feet on a footstool or cushions when sitting.
- Cool water soaks for hands or feet, followed by gentle movement.
- Move regularly: ankle circles and gentle walking help reduce puffiness in the feet and ankles.
- Loosen rings and watches, and choose comfortable, adjustable sandals or shoes, because feet often swell in the heat.
If one joint becomes suddenly hot, red, swollen and very painful, especially with a fever or feeling unwell, do not assume it is the heat. This can be a joint infection, which needs urgent help.
Staying active in hot weather
Regular activity remains important. NICE's osteoarthritis guideline (NG226) recommends exercise as a core treatment, and long spells of sitting still make stiffness worse. In a heatwave:
- Exercise early or late, when it is cooler, and avoid the hottest part of the day.
- Swimming and water exercise are excellent in hot weather. Water supports your weight and keeps you cool. See our swimming for arthritis guide.
- Indoor routines: seated or standing exercises in the coolest room of the house. Our exercise hub has ideas.
- Shorter sessions: do a little and often rather than one long session.
- Drink before, during and after activity.
- Stop if you feel dizzy, sick, very tired or have a headache, and cool down straight away.
Medicines and hot weather
Some medicines can affect how your body copes with heat or how your skin reacts to sun. Do not stop any medicine because of the heat, but do check:
- Ask your pharmacist whether any of your medicines may make you more affected by heat or more sensitive to the sun. Water tablets (diuretics) and some blood pressure, heart and mental health medicines are among those that can affect fluid balance or heat tolerance.
- Read the leaflet for each arthritis medicine. Some can make skin more sensitive to sunlight, so use high-factor sunscreen and cover up.
- Anti-inflammatory painkillers can affect the kidneys, and being dehydrated may increase this risk. If you are unwell with vomiting, diarrhoea or are struggling to drink, ask your pharmacist or GP whether you should pause them.
- Storage: most medicines should be kept below 25°C. Keep them out of direct sun and hot cars. Injectable biologics usually need to be kept in the fridge; follow the storage instructions and ask your homecare provider or pharmacy for advice if you are travelling.
- Infection risk: if you take immune-suppressing medicines, take care with food hygiene at barbecues and picnics, and keep food chilled.
Sleeping in the heat
- Keep your bedroom curtains closed during the day and open windows at night if it is safe to do so.
- Use a single light cotton sheet rather than a duvet.
- A cool shower before bed can help you settle.
- Put a cold pack wrapped in a towel near swollen joints, but do not fall asleep with ice directly on your skin.
- Keep a glass of water by the bed.
- If you cannot sleep, the NHS suggests getting up and doing something relaxing until you feel sleepy. See our guide to sleeping with arthritis.
Pacing in a heatwave
Heat is tiring, so pace yourself. Plan chores, shopping and errands for the early morning. Break tasks into smaller pieces with rests in a cool place. Accept that you may get less done during a hot spell. Our pacing guide explains how to plan your energy.
Eating and drinking well in hot weather
- Drink regularly through the day; do not wait until you feel thirsty. Water, diluted squash, milk and decaffeinated drinks all count.
- If your doctor has told you to limit fluids, for example because of a heart or kidney condition, ask them what to do in a heatwave.
- Eat cold, lighter meals such as salads, fruit, yoghurt and sandwiches. Fruit and vegetables also contain water.
- Avoid alcohol, which increases dehydration. For gout, the NHS advises drinking plenty of fluids to avoid dehydration and having alcohol-free days.
Holidays in hot countries
If you are travelling somewhere hot, pack medicines in your hand luggage with a copy of your prescription, plan for keeping fridge medicines cool, and check travel insurance covers your conditions. Our guide to travelling with arthritis medicines has a checklist.
Heat exhaustion and heatstroke: know the signs
The NHS lists symptoms of heat exhaustion including tiredness, dizziness, headache, feeling or being sick, excessive sweating with pale, clammy skin, cramps in the arms, legs and stomach, a high temperature, being very thirsty and feeling irritable.
If someone has heat exhaustion, the NHS advises four steps: move them to a cool place; remove unnecessary clothing; give them plenty of water (an isotonic sports drink or oral rehydration solution is fine too); and cool their skin by spraying or sponging with cool water and fanning them. Cold packs wrapped in a cloth under the armpits or on the neck also help. Stay with them. They should start to feel better within 30 minutes.
Heatstroke is a medical emergency. Signs include a very high temperature, hot skin that is not sweating, fast breathing and heartbeat, confusion, a seizure or loss of consciousness.
When to get medical help
- Call 999 for signs of heatstroke, including still being unwell after 30 minutes of resting in a cool place, being cooled and drinking fluids; a very high temperature; hot skin that is not sweating; a fast heartbeat or fast breathing; confusion or lack of coordination; a seizure; or loss of consciousness. Do not drive yourself to A&E.
- Call NHS 111 or go to A&E for a suddenly hot, red, swollen, very painful joint, especially with fever or feeling unwell.
- Call NHS 111 if you are struggling to treat heat exhaustion symptoms or need advice, or if you are struggling to drink because of vomiting or diarrhoea and take medicines that may be affected.
- See your GP or rheumatology team if joint swelling in the heat does not settle when it cools down, or if your arthritis is regularly flaring.
- See a GP if you think you have gout for the first time.
Is hot weather good or bad for arthritis?
It varies. Many people feel less stiff in warm weather, while others, including some with inflammatory arthritis, notice more swelling and tiredness in heat and humidity. Very hot weather brings risks such as dehydration and heat exhaustion, so follow NHS heatwave advice.
Why do my joints swell in hot weather?
Heat can make blood vessels widen and fluid collect in the hands, feet and ankles, which can make joints feel tight and puffy. Raising your legs, moving regularly and cool soaks can help. Swelling of one hot, painful joint with fever needs urgent advice.
Should I use ice or heat on joints in a heatwave?
Cold usually feels better on swollen, warm joints in hot weather. Use a cold pack wrapped in a towel for 10 to 15 minutes. Avoid ice directly on the skin, and take care with cold if you have Raynaud's phenomenon or reduced feeling.
Can I exercise with arthritis in hot weather?
Yes, but avoid the hottest part of the day, between 11am and 3pm. Exercise early or late, choose swimming or indoor routines, drink plenty and stop if you feel dizzy, sick or very tired.
Do arthritis medicines make you more sensitive to the heat or sun?
Some can. Certain medicines can affect fluid balance, heat tolerance or how your skin reacts to sunlight. Read the leaflet for each medicine and ask your pharmacist. Do not stop any medicine without speaking to your GP or pharmacist.
How should I store biologic injections in a heatwave?
Follow the storage instructions for your medicine. Most biologics are kept in the fridge and should not be left in hot rooms, cars or direct sun. If you are unsure, or are travelling, ask your homecare provider, pharmacy or rheumatology team.
Sources and further reading
- NHS: Heatwave – how to cope in hot weather
- NHS: Heat exhaustion and heatstroke
- NHS: Gout
- NHS: Rheumatoid arthritis
- NHS: How to get to sleep
- NICE NG226: Osteoarthritis in over 16s
Educational information for people in the United Kingdom — not a diagnosis or personal medical advice. Charity no. 1218461. Pending clinical review. Everyone's situation is different, so always follow the advice of your own GP, pharmacist or rheumatology team. If you feel very unwell, call 999 or go to A&E. For urgent advice, contact NHS 111.
Continue with related help
- Heatwaves and frailty — extra care for older adults
- Weather and arthritis pain — what research shows
- Arthritis in winter — the cold-weather plan
- Swimming — joint-friendly summer exercise
- Heat vs ice — using cold on swollen joints
- Travelling with medicines — holidays in the heat