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  • Writer's pictureAqua Warehouse

Are Hot Tubs Safe - What are the Potential Dangers and Side Effects?

Updated: Jan 4, 2023

The answer is yes, generally, for the average bather, but there are some things you need to be aware of if you want to use a hot tub safely.

Nothing quite matches the luxurious feel of lying back in your own hot tub. The bubbly, warm water soothes aches and pains, loosens tight muscles, reduces swelling, and alleviates painful joints. Hot tubs have also been shown to ease stress and promote relaxation. But are hot tubs safe?

Hot tub water jets may be particularly soothing, but potential dangers might be lurking within them. The hot tub installation must be done correctly, and regular maintenance is also a must to ensure the safety of everyone who uses the tub/spa.

Are you in the process of purchasing your first hot tub/spa? Or simply wondering, are hot tubs unhealthy? Or are there any negative effects of hot tubs? Here are some things you must know.

Are Hot Tubs Considered Generally Safe?

A hot tub is generally safe to use, provided you:

  • Keep the tub clean

  • Maintain the water clean and clear

  • Ensure there are no unusual chemical/chlorine odours

  • Don't allow people with sensitive medical conditions to use it

Can Hot Tubs Cause Health Problems and be Toxic?

Hot tubs are generally considered safe for the average bather. But they may cause problems for some people with specific medical conditions. Often, people purchase a hot tub but are unaware of the dangers that could lurk beneath the surface.

The warm water of a hot tub/spa must be kept at a specific temperature to be safe. Incorrect water temperature may increase bacterial growth. Hot tubs can be the perfect breeding ground for bacteria - so effective disease control is essential.

Poor quality water may also pose a health risk to tub users. Not correctly taking care of your hot tub may result in a greater risk of funguses and viruses. There is also an increased risk of contracting Legionnaires disease.

Avoid overheating the water in a hot tub. Excessive water temperature also increases the risk of accidental injuries such as scalding or burning. Hot tub-related injuries such as slipping should also be a concern. Textured surfaces and slip-proof hot tub steps can help mitigate the risks and avoid an emergency room visit.

The chemicals used in treated recreational water, such as in a swimming pool, spa, or hot tub, also pose health risks if the wrong amounts are added.

Hot tub owners have a responsibility to ensure everyone using it is safe. Read on and learn how to keep your family and yourself healthy and happy while enjoying a hot tub soak.

What are the Most Common Hot Tub Side Effects and Risks?


Failing to maintain and clean your hot tub correctly may lead to a user contracting an infection caused by viruses or bacteria in it. Common issues include ear, eye, and skin infections, but other more serious diseases are also a threat.


Bathing in an unclean hot tub can result in a bumpy red rash known as hot tub rash (hot tub folliculitis). The rash is caused by the germ Pseudomonas aeruginosa. It can develop in your hot tub and cause health issues for users vulnerable to health risks.

Bacteria and Parasites

Using chlorine to keep hot tub water clean eliminates most parasites and bacteria, but not all. A variety of different parasites and bacteria are chlorine-resistant and can cause problems. Some of the most common include:

Shigellosis and E coli

These bacteria can quickly spread in dirty hot tub water. Bacteria can enter your stomach, as there is always a risk of ingesting water when using a hot tub. How do you reduce the risk of bacteria causing problems? Frequently change and shock your hot tub water to sanitize it.


  • Stomach pain

  • Diarrhoea

  • Fever

Pseudomonas Aeruginosa

These bacteria are harmful microorganisms that can cause a condition known as hot tub rash. According to the Centers for Disease Control and Prevention (CDC), it is a common illness linked to hot tubs. The bacteria is common in the environment, but the condition is caused when the skin is exposed to contaminated water for an extended time. You can reduce the risk of this bacteria by disinfecting your hot tub using chlorine and maintaining the correct pH level, between 7.2 to 8.


  • Red, itchy bumps and itchy skin

  • Pus-filled blisters around hair follicles

This bacteria can also cause UTIs (Urinary Tract Infections). There have been several reported cases, for example, three cases in Denver, and a case in New York.


Legionella is a bacteria that may lead to people contracting Legionnaires’ disease. It is also a bacteria commonly found in water left sitting for prolonged periods or which has not been properly disinfected. Use a high-quality disinfectant in hot tub water to eliminate Legionella contamination. Legionnaires disease infection occurs when you inhale mist or steam in a contaminated hot tub.

Symptoms of Legionnaires disease usually develop within 24 hours of soaking in a hot tub.


  • Muscle aches

  • Chills

  • Fever

  • Headache


Giardia is a hot tub parasite found in contaminated water. This parasite is tolerant to chlorine and can cause giardiasis.


  • Abdominal and stomach cramps

  • Dehydration

  • Diarrhoea


This is another common chlorine-tolerant parasite. In the US, crypto is one of the most common waterborne diseases caused by ingesting the parasite via contaminated water. People with a healthy immune system usually recover without the need for medical intervention.


  • Vomiting

  • Fever

  • Diarrhoea


Dehydration is a common side-effect when using a hot tub, caused by the temperature difference between the hot water and outside air. The best way to prevent dehydration is to drink lots of liquids and keep the hot tub temperature low.

Irritation From Bodily Fluids

It may not be the nicest of topics to discuss, but hot tub users must fully understand the risks. Hot tubs can become contaminated with faecal matter bacteria, according to a University of Arizona professor of microbiology and environmental studies.

Faeces, sweat and urine can react with the chlorine and form chloramine. Chloramine can lead to skin irritation, sometimes severe for people with sensitive skin.


People often experience headaches after using a hot tub. A "hot tub headache" is the result of the temperature difference between the hot tub's water and the outside air.


Feeling sick and vomiting can be caused when the hot tub's temperature is too hot. Try to keep the hot tub temperature low, stay in the shade, and drink plenty of liquids.


Some people feel dizzy after using a hot tub. The cause is usually the temperature difference and overheating of the body. The best way to avoid dizziness is to soak in the tub for shorter periods and stay hydrated.


Fainting can be caused by the water's heat. Limiting the time spent soaking to around fifteen minutes reduces the risks of feeling faint.

Dry Skin

Soaking in very hot water for extended periods can cause dry skin. The best way to avoid dry skin is by reducing the water temperature in the tub/spa.


It is more common for thermal burns to be associated with water than fire. However, you'd have to sit in water that was 113°F (45°C) for two hours before getting severe second-degree burns. So always ensure the water is no more than 104°F (40°C). According to experts, healthy adults should never spend over fifteen minutes in a hot tub at any time, even when wearing a bathing suit.

Hyperthermia (Overheating)

Overheating or hyperthermia is another common side-effect of using hot tubs. It's caused by sitting in hot water for long periods.


The chemicals used to disinfect and clean hot tubs can cause an allergic reaction in some people. One of the biggest culprits is a chemical known as PPMS or potassium peroxymonosulfate. People use this to remove organic contaminants from their hot tubs using a process referred to as oxidation.

Who Should Avoid Hot Tubs?

Hot tubs are, generally, safe for most people. But certain groups of people are more at risk of suffering some of the side effects mentioned above.

Can You Go in a Hot Tub While Pregnant?

Pregnant women are generally advised not to use hot tubs for too long as doing so will increase body temperature.

Research also shows that when pregnant women use a hot tub more than once or for long periods, doing so increases the risk of their babies having neural tube birth defects such as anencephaly or spina bifida.

For maximum safety, pregnant women should avoid hot tubs during pregnancy because of the risk of birth defects. Pregnant women who want to use a hot tub should turn down the temperature, to avoid overheating and limit hot tub time to less than ten minutes.

For more information, read our guide: are hot tubs safe for pregnant women?

Can Children Go in Hot Tubs?

Any sensible parent will already be aware of the risks of leaving their children alone near water. The same applies to hot tubs.

It's easy for young children to overheat and drown in spas and hot tubs. All it needs is a couple of inches of water for a child to drown.

A risk for parents who own a home hot tub is that their child will climb in unnoticed. So it's best to keep your hot tub covered when not in use. Most hot tubs come with a cover.

Can Babies Go in Hot Tubs?

Toddlers and infants under the age of two should not be allowed in a hot tub because their sensitive skin makes them more susceptible to overheating. There is also the risk of “accidents” as babies don't have much control over their bodily functions.

Generally, children under the age of five should not be allowed in a hot tub. After that age, they should be tall enough to stand with their head above the water.

Can Seniors Use Hot Tubs?

There are some health risks associated with the elderly using hot tubs because they are perfect breeding grounds for bacteria that cause infections. Older people are also more prone to chronic lung problems, heart conditions, and high or low blood pressure.

Seniors with these issues should avoid using hot tubs, as should those taking certain medications for any medical condition.

Can People With Heart Disease Go in Hot Tubs?

If you suffer from heart disease, first consult your doctor. Take great care when using a hot tub because your body can't sweat while sitting in hot water. So to lower your body's temperature, the blood vessels dilate. In turn, this lowers your blood pressure causing your heart to beat faster.

For healthy people, low blood pressure isn't an issue. However, lower blood pressure strains the hearts of people with heart disease.

Hot Tub Safety Tips

If you want to keep yourself and your loved ones safe when using a hot tub, here are some tips:

  • If unsure whether it's safe to use a hot tub, ask your doctor for their advice.

  • Maintain a healthy water temperature of around 100°F (37.77°C).

  • Ensure your hot tub is clean and the chlorine and pH levels are correct.

  • Test the water before getting in.

  • Avoid jumping from a hot tub into a cool pool, as this could shock your system and raise your blood pressure.

  • Don't stay in your hot tub for too long; 10 minutes should be the limit.

  • Avoid using bubble bath.

  • Don't wear oily lotions.

  • Stay hydrated.

  • Avoid drinking alcohol, as this can dehydrate you even further.

  • Watch your step getting in/out.

  • Have a shower afterwards.

  • Stay away if the hot tub is full of people because more people equals more germs.

  • Ensure the safety of other hot tub users.

What is the Safest Hot Tub Temperature?

The safest maximum temperature in your hot tub is no higher than 104°F (40°C), but the ideal temperature considered safe for an adult is 100°F (37.77°C).

What are the Health Benefits of Using a Hot Tub?

There are many health benefits from soaking in a hot tub. Here are just a few examples, some of which are scientifically proven and others anecdotal:


We understand your hot tub might feel like a real luxury at the end of the day, and you can't wait to soak your stress and worries away, but you must be aware of some things. Always take care when using your hot tub. Keep the water in your hot tub clean, and ensure you rinse yourself off before getting in and after enjoying your soak.


How long is it safe to be in a hot tub?

You'll find the answer to this question depends on what source you read and other factors such as age and water temperature. A general rule is that the maximum safe time to soak in a hot tub is between ten and fifteen minutes. If the water temperature is between 95 and 100°F, you could stay in your hot tub for up to thirty minutes.

Can I drink alcohol while in a hot tub?

Avoid drinking alcohol while soaking in a hot tub because alcohol dehydrates you, expands your blood vessels, and raises your body temperature. Add dehydration into the equation, and it could lead to heat exhaustion.

Can I use my hot tub without chemicals?

Do not do this because your hot tub will become unsafe. Without chemicals in the water, contaminants can cause serious side effects.

How long after putting chemicals in a hot tub can I use it?

Generally, you should wait a minimum of thirty minutes after adding chlorine before getting in your hot tub.

Is it safe to go in a hot tub every day?

Yes, it is perfectly safe to use your hot tub every day. But you must clean it regularly and test the water to ensure the pH level is correct and there are no contaminants.

Are hot tubs bad for the liver?

The reverse is actually true. Soaking in a hot tub can reduce strain on your liver and kidneys.

Do hot tubs cause spider veins?

No. Hot tubs don't cause spider veins, but the hot water can worsen symptoms.

Can I get scabies from a hot tub?

Catching scabies from a hot tub is highly unlikely.

Can I get ringworm from а hot tub?

You can only get ringworm from direct skin-to-skin contact in water, so, theoretically, it would be difficult to catch it in a hot tub.

Can hot tub users get an STD from a hot tub?

The only way you can get an STD from using a hot tub is by having sex with an infected person while in the tub.

Can hot tub use cause blood clots?

Using hot tubs can be extremely dangerous for someone with a blood clot. This is because the heat can help dislodge the clot and allow it to travel to the lungs. This is known as a pulmonary embolism.

Can hot tubs cause kidney infections?

No. Hot tubs cannot cause kidney infections.

Can hot tub use cause yeast infections?

Hot tubs can't cause yeast infections. But sitting in a hot tub may make you more susceptible to yeast infection because the humidity and heat are the perfect environments for yeast to grow.

Can hot tubs damage the lungs?

Hot tub lung is a disorder caused by inhaling water that contains non-tuberculous mycobacteria (NTM). The symptoms are asthma-like and can be life-threatening.

Can a hot bath cause a stroke?

There is no proof that taking a hot bath can cause a stroke. Research has shown that a daily hot bath can reduce the overall health risks of cardiovascular disease; overall, by 28% and by 26% for stroke. The results are compared with those of people who bathe twice a week or less frequently.

Is it good to go in a hot tub in the morning?

Enjoying a soak can be an excellent start to the day because it relaxes and relieves any muscle aches. The natural buoyancy of the water also reduces pressure on your back, feet, and legs.




Jess Court

I'm Aqua Warehouse Groups Marketing Officer - overseeing all things news worthy in the hot tub industry, with tips and tricks that are bound to make a splash.

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