Can you go in a hot tub with a fever?

Can you go in a hot tub with a fever? No. If your temperature is 38°C (100.4°F) or higher, keep the cover on. Hot water stops your body from shedding heat, so your temperature climbs further, and a fever already leaves you dehydrated and more likely to feel faint. You could also pass the illness on to others.

The good news is that the wait is usually short. Once your temperature has been normal for at least a day without any fever-reducing medicine, and you feel well, most people can go back to normal soaks. The sections below explain the reasons and give you a simple checklist for getting back in.

This article is general information, not medical advice.

Can you go in a hot tub with a fever?

A fever is your body deliberately raising its own temperature to fight an infection. Your brain resets its internal thermostat higher, and your heart, lungs and blood vessels work harder to hold you at that new level. You are already running hot on purpose.

There is a reason for this. A higher temperature makes your body a less hospitable place for the virus or bacteria causing the illness, which helps your immune system fight it. Your body is already managing that heat carefully, so it does not need extra heat from outside.

Your body normally cools itself in two main ways: by sending warm blood to the skin so heat can escape into the air, and by sweating so that evaporation carries heat away. Both of these depend on the air or water around you being cooler than your skin.

What hot tub water does to a raised temperature

Most hot tubs run between about 37°C and 40°C (98.6°F to 104°F), and 40°C is the widely accepted upper limit. Water at that temperature is warmer than your skin, so instead of losing heat you gain it. Sweat cannot evaporate from skin that is underwater, so your main cooling system stops working.

For a healthy person, this is why a soak feels relaxing for a while and then starts to feel too much. For someone with a fever, the starting point is already high. The extra heat pushes the temperature up further and faster, which can leave you dizzy, confused or nauseous.

The danger here has a name: hyperthermia. This is a body temperature above about 40°C (104°F), at which your body can no longer control its own heat. A fever is a higher setting that your body still manages. Hyperthermia is heat building up faster than you can lose it, and a hot tub on top of a fever moves you towards it.

Someone already weakened by illness overheats faster than a healthy person and moves through the warning signs more quickly. Dizziness can turn into confusion or fainting before you have time to react, so waiting until you feel bad before getting out is not a safe plan.

The extra strain on your heart

A fever already makes your heart beat faster. Hot water widens your blood vessels, and your heart has to pump even more blood to the skin to try to lose heat. Together, these put extra strain on the heart, which matters most for anyone with a heart condition.

When hot water draws blood to the skin, less of your circulation reaches your vital organs, such as the brain, heart and kidneys. This comes on top of the faster heart rate and the lower blood pressure that heat causes, and an illness makes all three harder for your body to cope with.

Why young children are at extra risk

Young children heat up faster than adults because they are smaller. In a young child, extra heat on top of a fever can push the temperature up quickly, and a fast rise can trigger a febrile seizure. This is a fit caused by a high temperature, and it is another reason to keep a feverish child out of a hot tub completely.

Why it can feel good at first

When a fever is rising, you often feel cold and shivery even though your temperature is high. Warm water can feel very comforting in that moment. That comfort is misleading: it is your body asking for heat while it is already overheating, and the effect does not help you recover.

If you have a temperature of 38°C (100.4°F) or above, do not use a hot tub, sauna or steam room. Wait until your temperature has been normal for at least 24 hours without paracetamol or ibuprofen, and you feel well again.

What temperature counts as a fever?

The NHS says a normal body temperature for most people is around 36°C to 37°C, and treats 38°C (100.4°F) or higher as a high temperature. You can read the NHS guidance on high temperature (fever) in adults for the full advice.

Readings between 37.2°C and 37.4°C (99°F to 99.3°F) are a caution zone rather than clearly normal. Check your temperature again after a short while, and skip the soak if you feel at all unwell. This matches the 37.2°C cut-off given later in this article for soaking with a cold.

Readings between 37.5°C and 37.9°C (99.5°F to 100.2°F) are often described as slightly raised. They are not a reason to panic, but they do tell you that your body may be fighting something. Hot water on top of that is still a poor idea.

If your reading is in this slightly raised range, recheck it about every 30 minutes. If it climbs towards 38°C, treat the hot tub as strictly off-limits until the fever has fully passed.

A slightly raised temperature is an even stronger reason to stay out if you are an older person or have an underlying health condition, such as heart disease, diabetes or a weakened immune system. Your body has less in reserve to cope with extra heat and fluid loss.

How a fever rises, peaks and breaks

A fever usually follows a pattern. It rises, often with chills and shivering, then reaches a peak, and finally breaks as your body lets the temperature fall, usually with heavy sweating.

Fevers are sometimes described in five stages: onset, rising, peak, falling and resolution. Only the resolution stage, when your temperature is back to normal on its own, starts the 24-hour clock before your next soak. A temperature that is still falling does not count.

The rising and peak stages put the most strain on your body's heat control, so they are the worst times to add hot water. Sweating as a fever breaks is a good sign, but it does not mean it is safe to soak. The fever can return, and the 24-hour rule still applies.

Taking an accurate reading

Use a digital thermometer under the tongue or in the armpit, or an ear thermometer, and follow its instructions. Do not take your temperature straight after a hot drink, a shower or a hot tub session, because the reading will be falsely high. Wait at least 20 to 30 minutes first.

Feeling hot to the touch, shivering, or feeling warm and sweaty are all signs of a fever even if you do not have a thermometer. If you have those symptoms, treat it as a fever until you know otherwise.

Why are dehydration and fainting such a risk?

A fever increases the amount of fluid you lose through your skin and breath. Many people also eat and drink less when they feel ill, and some illnesses add vomiting or diarrhoea. By the time you think about a soak, you may already be short of fluid.

Thirst is not a reliable guide. People with a fever are often already dehydrated before they feel thirsty, so if you wait until you want a drink, you are already behind.

Hot water makes this worse. You sweat in a hot tub even though you cannot see it, because the sweat mixes straight into the water. Our guide to how much you sweat in a hot tub explains why the loss is easy to underestimate.

In someone who is ill, even a 15 to 20 minute soak can turn mild dehydration into moderate dehydration. That tends to make headache, tiredness and dizziness worse, and it makes the fever harder to manage afterwards.

How fainting happens

Heat widens your blood vessels so more blood flows to the skin. That lowers your blood pressure. If you are also dehydrated, there is less fluid in your blood to start with, so the drop is larger.

The most dangerous moment is often standing up to get out. Blood pools in your legs, less reaches your brain, and you can feel light-headed or black out. Hot tub steps are wet and hard, so a faint at that point can lead to a fall or a head injury.

Early warning signs that your core temperature is getting too high, or that you are dehydrated, include:

• Dizziness or light-headedness
• A headache that gets worse in the water
• Feeling sick or being sick
• A pounding or fast heartbeat
• Confusion or difficulty concentrating
• Loss of coordination or feeling clumsy
• Dark yellow urine or not passing much urine
• Muscle cramps or weakness

If you notice any of these during a soak, even when you are well, get out slowly, sit somewhere cool and drink water. The NHS page on dehydration lists symptoms that mean you should get medical help.

Can you pass your illness on to others in a hot tub?

Yes, it is possible, and the water is only part of the picture. A hot tub puts several people close together, face to face, breathing warm, moist air. Coughs, sneezes and close conversation can spread colds, flu and COVID-19 in the same way as any small shared space.

Well-kept water helps a great deal. Free chlorine at 3-5 ppm or bromine at 3-5 ppm, with pH at 7.2-7.6, kills most bacteria and viruses. It does not work instantly, though, and some germs are far more resistant than others.

Bacteria in poorly kept water

When sanitiser levels drop, hot tub water can grow Pseudomonas bacteria. These cause an itchy, bumpy rash called hot tub folliculitis. Testing regularly and keeping sanitiser in range is the main defence.

Warm, aerated hot tub water lets bacteria multiply quickly as soon as sanitiser levels slip. This is why poorly kept hot tubs are one of the leading causes of outbreaks of recreational water illness, meaning illness spread through pools, hot tubs and similar shared water.

To lower the risk of spreading germs, everyone should shower with soap before and after a soak. Change out of a wet swimsuit promptly afterwards rather than sitting around in it.

Hot tubs and urinary tract infections

Hot tub use can raise the risk of urinary tract infections (UTIs), especially in women, because the tube that carries urine out of the body is shorter. Long soaks, shared water and sanitiser chemicals that upset the natural balance of bacteria around the genitals all add to the risk.

Frequent hot tub use is linked to repeat UTIs in people who are prone to them. If that applies to you, keep sessions shorter and less frequent, and speak to your GP if infections keep coming back.

Urinate soon after a soak to help flush out bacteria and lower the risk of a UTI. Then shower and change into dry clothes.

Stomach bugs are a special case

Germs that cause diarrhoea and vomiting are the biggest concern for shared water. Some, such as cryptosporidium, can survive normal chlorine levels for days. Never use a hot tub with diarrhoea, and the NHS advises not swimming for 2 weeks after diarrhoea stops if you have had cryptosporidiosis.

The CDC's healthy swimming guidance covers how germs spread in pools and hot tubs and why staying out when ill protects everyone who shares the water.

Other people in your household

If one person in your home has a fever, others may already be incubating the same illness. It is sensible for everyone to keep sessions short and step out at the first sign of a sore throat, chills or tiredness.

Is a hot tub safe with a cold, flu, COVID-19 or other illnesses?

The fever rule applies whatever the cause. Beyond that, some illnesses need extra care. If your GP or pharmacist has given you specific advice, follow it over any general guidance here.

A hot tub will not shorten an illness or speed up your recovery. Even without a fever, soaking while you are unwell can cause dehydration, dizziness and extra strain on your heart, so the safest choice is usually to wait until you feel better.

A cold without a fever

With a mild head cold and a normal temperature, a short soak at a lower setting, around 36°C to 37°C, may ease a blocked nose for a while. It may also ease muscle aches and help you sleep. Keep it brief, drink water, and soak alone or only with people you live with. If you start to feel worse, get out.

Check your temperature before you get in every time, because a cold can develop into a fever.

Only get in if your temperature is below about 37.2°C (99°F). Keep the session to no more than 15 to 20 minutes, and drink water before, during and after your soak.

At any point during the soak, get out straight away if you feel dizzy, light-headed or unusually warm. Sit somewhere cool, drink water and do not get back in that day.

Flu and COVID-19

Flu and COVID-19 often bring a high temperature, aching muscles and exhaustion. Stay out until your temperature has been normal for at least a day without medicine and you have your energy back. UK guidance is to try to stay at home and avoid contact with others while you have a high temperature or feel unwell.

COVID-19 can also strain the heart and circulation. That means even a private hot tub with no one else in it adds risk during an active infection.

Aching after an illness is common, and it can be hard to tell it apart from soreness after a soak. Our article on why your body can ache after a hot tub explains the usual causes.

Chest infections and pneumonia

Pneumonia and other chest infections put real strain on your lungs and heart. Hot, humid air can make breathing feel harder, and recovery often takes weeks rather than days. Ask your GP when it is safe to return to a hot tub, and start with short, cooler sessions.

Pneumonia can also cause very high fevers, which adds to the risk from hot water.

Glandular fever (mono)

Glandular fever can cause a fever and tiredness that last for weeks. It can also make the spleen swell, which is why doctors often advise avoiding contact sports and heavy activity for a time. Wait until the fever has gone and your energy returns, and check with your GP if you are unsure.

During the acute phase of glandular fever, when symptoms are at their worst, the heat stress of a hot soak can make the exhaustion, aching and other symptoms worse. In rare cases, the extra strain on your body may also add to the risk of complications, so stay out of the hot tub during this phase.

Glandular fever spreads easily through saliva, so sitting close together in a shared hot tub risks passing it on. Before using a hot tub again, wait until a doctor has confirmed that your spleen is no longer enlarged.

If you use a hot tub on medical advice

Some people use a hot tub on medical advice for a long-term condition such as arthritis or fibromyalgia. That advice does not cover using it during an illness or fever. If you are unwell, ask your doctor whether and when to start again.

Skin infections, cuts and urinary tract infections

Keep out of the water with an infected cut, a weeping rash or a skin infection, to protect both you and others. With a urinary tract infection, warm water will not cure it and a fever is a sign it may be getting worse. If you are on treatment, see our guide to using a hot tub while taking antibiotics.

What about a swimming pool?

Pool water is usually kept at around 25°C to 28°C (77°F to 82°F), so it does not add heat in the same way as a hot tub. However, the effort of swimming raises your heart rate and body temperature, which cancels out the benefit of the cooler water.

Swimming also uses energy you need for recovery, and shared pools spread illness. Stay out of public pools while you have a fever, and wait at least 48 hours after any diarrhoea or vomiting has stopped.

Staying out of the pool does not end when the fever breaks. Apply the same rule as for a hot tub: wait until you have been fever-free for 24 hours without paracetamol or ibuprofen before you swim again.

What helps a fever instead of a hot soak?

There is a popular idea that you can sweat out a fever or an infection. It is not true. Sweating cools you and loses fluid, but it does not remove viruses or bacteria, and adding heat on purpose only increases the strain on your body.

The sweat you lose in hot water is your body trying to cool down. It is not the illness leaving your body.

The NHS suggests simple steps for adults with a high temperature:

• Rest as much as you can
• Drink plenty of fluids, little and often, so your urine is pale
• Take paracetamol or ibuprofen if you feel uncomfortable, following the dose on the pack
• Wear light clothing and keep the room comfortably cool
• Use a light sheet or blanket rather than piling on layers

A few more things can help you feel better:

• Choose clear fluids such as water, broth, herbal tea or diluted juice
• As a rough guide, aim for about 8 to 10 glasses of water or clear fluids a day while you have a fever
• Drink extra if you are sweating heavily
• Get plenty of sleep, around 8 to 10 hours a day, because rest lets your body put its energy into fighting the infection
• Keep the bedroom at around 18°C to 20°C (65°F to 68°F)

Is a lukewarm bath or shower a good idea?

A lukewarm shower or bath can help you feel fresher and more comfortable. Aim for roughly 29°C to 35°C (84°F to 95°F), which should feel slightly cool on the inside of your wrist. Avoid cold water, which can make you shiver and raise your temperature again.

A lukewarm bath is most useful when paracetamol or ibuprofen alone is not giving you enough relief from the fever. It adds comfort alongside medicine rather than replacing it.

Soak for no more than 10 to 15 minutes so you do not get chills afterwards, and have someone nearby if you feel weak or dizzy. Sponging your forehead and neck with a damp cloth can add a little extra comfort.

When you get out, pat yourself dry gently rather than rubbing hard, and drink a glass of water straight away. Rubbing hard with a towel creates friction that warms your skin, which works against the cooling effect of the bath.

Easing a blocked nose without getting in

If the steam is what you miss, a warm shower or breathing in the steam from a hot drink can ease congestion for a short time. Do not lean over a bowl of very hot water, as scalds are common, especially with children around.

When is it safe to go back in the hot tub?

A common rule of thumb, used by many schools and health bodies, is to wait until you have gone 24 hours without a fever and without fever-reducing medicine. Paracetamol and ibuprofen lower your temperature for a few hours, so a normal reading taken while they are working does not mean the fever has gone.

If your temperature is only normal because of medicine, you may also still be infectious to others. That is another reason to stay out of a shared hot tub until the fever has gone on its own.

The same 24-hour fever-free rule is the usual guide for going back to work, school and other shared activities, so it is an easy standard to remember.

Follow these steps for your first soak back:

1. Check your temperature has been normal for at least 24 hours without paracetamol or ibuprofen.
2. Make sure you have no diarrhoea or vomiting for at least 48 hours, and longer if your GP has advised it.
3. Drink a glass of water before you get in.
4. Lower the water temperature to around 36°C to 37°C for your first session.
5. Keep the first soak short, around 10 minutes, and have someone at home who knows you are in.
6. Get out slowly, sitting on the edge for a minute before you stand.
7. Drink more water afterwards and stop using the tub if any symptoms return.

Build back up gradually over a few days. Our guide on how long to stay in a hot tub covers sensible session lengths, and many manufacturers give their own limits, so check your manual.

Looking after the water after illness

If someone used the tub while unwell, or just before symptoms started, give the water some attention before others get in:

1. Test free chlorine or bromine, pH and total alkalinity.
2. Shock the water according to your product instructions.
3. Run the filtration with the cover open for the time your product recommends.
4. Rinse or clean the filter, or swap in a clean spare.
5. Retest and bring sanitiser back to 3-5 ppm and pH to 7.2-7.6 before anyone uses the tub.
6. If there was an accident involving diarrhoea or vomit in the water, drain, clean and refill rather than relying on chemicals.

For more on keeping everyone safe day to day, see our hot tub safety rules everyone should know.

When should you speak to a GP or call 111?

Most fevers in adults clear up on their own within a few days. Speak to a pharmacist for advice on medicines, and contact your GP or NHS 111 if:

• Your temperature is very high, or you feel hot and shivery and paracetamol is not helping
• Your temperature is 39.4°C (103°F) or higher, in which case seek advice promptly
• The fever lasts more than 3 days without improving, or keeps coming back
• You are over 65, because even a moderate fever carries a higher risk, so seek advice sooner
• You have a long-term condition, a weakened immune system or are having chemotherapy
• You are pregnant, in which case also speak to your midwife
• You feel unwell with other worrying symptoms, such as pain when you urinate

If you are unsure how serious a fever is, or you have lost track of how long it has gone on, contact NHS 111 or your GP for advice rather than waiting to see what happens. NHS 111 is available online or by phone at any time of day. Outside the UK, use your local health advice line.

Call 999 or go to A&E if you or someone else has a fever with any of these:

• A stiff neck or pain when looking at bright lights
• A severe headache
• A rash that does not fade when you press a glass against it
• Difficulty breathing or chest pain
• Confusion, slurred speech or being very drowsy
• A seizure or fit

For babies under 3 months with a temperature of 38°C or higher, the NHS advises contacting a GP or NHS 111 straight away. Children with a fever should not use a hot tub at all.

The short version

Hot water and a fever do not mix. A hot tub stops your body from cooling itself, pushes a high temperature higher, adds to dehydration and makes fainting more likely when you stand up. It can also spread your illness to the people sharing the water and the air.

Rest, drink fluids and let the fever pass. Once your temperature has been normal for 24 hours without medicine and you feel well, start again with a short, cooler soak, check your water balance, and speak to your GP or pharmacist if you have any doubts.

Frequently asked questions

What should you not do when you have a fever?

Avoid anything that adds heat or drains fluid: hot tubs, saunas, steam rooms, hard exercise and alcohol. Do not pile on heavy blankets or sit in a hot room, and do not take more paracetamol or ibuprofen than the pack allows. Avoid close contact with others, especially older people, babies and anyone with a weakened immune system, until the fever has passed.

Is 37.5°C a fever?

The NHS treats 38°C (100.4°F) or higher as a high temperature. A reading of 37.5°C (99.5°F) is usually described as slightly raised. It often means your body is starting to fight something, so it is a good reason to rest, drink fluids and recheck later. Skip the hot tub until your temperature is back in your normal range and you feel well.

Can I use the hot tub once paracetamol has brought my temperature down?

No. Paracetamol and ibuprofen lower your temperature for a few hours but do not end the illness. When the medicine wears off, the fever usually returns, and you are just as likely to overheat or feel faint in the water. Wait until your temperature stays normal for at least 24 hours without taking any fever-reducing medicine.

Can I drink alcohol when I have a fever?

It is best to avoid it. Alcohol makes you pass more urine, so it adds to the dehydration a fever already causes. It can also make you feel better than you really are, which hides how unwell you are and makes it harder to judge when to rest or seek advice. Stick to water and other clear fluids until the fever has passed.

Do I need to drain the hot tub after someone with a fever used it?

Usually not. Shock the water, run the filtration, clean the filter and bring sanitiser back to 3-5 ppm and pH to 7.2-7.6 before anyone else gets in. Draining is advised if there was diarrhoea or vomit in the water, because some stomach bug germs resist normal chlorine levels. Wipe down headrests and handles too.

Is a sauna any safer than a hot tub with a fever?

No. A sauna or steam room raises your body temperature in the same way and causes heavy sweating, so the risks of overheating, dehydration and fainting are similar. Steam rooms also share warm, moist air between people in a small space. Treat all heat-based sessions the same: stay out until the fever has fully passed.

Can I use a hot tub if I am pregnant and have a temperature?

No. A high body temperature during pregnancy, especially in the early weeks, is something to avoid, and a hot tub adds more heat. Contact your midwife or GP about any fever in pregnancy, because they may want to check the cause. Ask them for advice on hot tub use in general, as many recommend avoiding or limiting it.