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What temperature should a hot tub be?

June 22, 2023 - Estimated read time - 7 minutes

Author – Fin Green - Content Creator UK, Jacuzzi Group 

Thinking of buying a hot tub, or already own one and wondering what the temperature of the hot tub water should be? Maybe you’re simply wondering why this matters.  

Comfort, health, age and energy usage are all factors that play into how hot or cold the water should be, and why.  

This article will answer the most common questions surrounding hot tub temperatures so you can feel confident about controlling your water, in the best way! 

Kimberley Walsh relaxing in a hot tub

Disclaimer - We, Jacuzzi Group, are not medical professionals. Any health-related information stated in this article is of a general nature and should not be taken as specific advice on any medical conditions, including their diagnosis or treatment. Nothing in this article is intended to prescribe any particular diagnosis or course of action, nor to constitute a claim that any product referred to can diagnose, treat or prevent any disease, injury, ailment or adverse condition. If you are in any way concerned about your current health or wellbeing, please make contact with your General Practitioner or other medical professional for advice, and in particular we encourage you to take independent medical advice before committing yourself to any significant treatment. 

Why does the temperature of hot tub water matter? 

The temperature of hot tub water matters for several reasons. This includes comfort, safety and effectiveness of massage. Maintaining the proper temperature of hot tub water is also important for a relaxing and therapeutic experience, while also preventing dehydration, and overheating.  



The ideal temperature for a hot tub is typically between 36-40°C. This is comfortable for most people, depending on your personal preference. If the water is too cold or too hot, it can be uncomfortable to soak in. 

Massage and effectiveness 

The temperature of the water can affect the hydrotherapeutic effectiveness of the hot tub. For example, if the water is too cold, it may not be able to provide the therapeutic benefits of a hot tub, such as relaxing muscles and soothing joints. On the other hand, if the water is too hot, it may cause fatigue and discomfort, instead of relaxation. 

Heat appears to have a unique ability to alleviate pain, which could be due to reduce blood flow speed. Some experts suggest that heat may also slow down sensory nerve pathways through thermal nervous terminations of the skin. Hot water can enhance blood flow and promote muscle relaxation.  

While a hot bath with hydromassage may provide immediate euphoria, prolonged exposure can be tiring to the body. Given that hydromassage baths are commonly used to reduce stress, it's crucial to manage the water temperature, in-line with the bathing time. 



If the water is too hot, it may cause people to suffer from overheating, dehydration, and even heat exhaustion. This is especially true for children, elderly, and people with health conditions. Because of this, it's important to keep the water temperature within a safe range.

Seats in a hot tub with no jets on

What temperature should I set my hot tub to? 

The exact temperature of a hot tub depends on personal preference. Many people enjoy theirs between 36°C and 38°C. The highest temperature a hot tub is recommended to be at is no higher than 40°C.  

What temperature should I leave my hot tub on overnight? 

It is a good idea to keep your hot tub on when not in use. If you set it to around 30°C when not in use, it should be able to retain some heat for your next use while keeping the bills at a minimum. 

If you are a regular hot tub user, it is best to leave the temperature. If you don’t use often, then there is more benefit for you to drop the temperature.  

For best advice that’s specific to your hot tub brand, model and usage, we recommend you speak to the salesperson or team who sold you your product. 

If you have Jacuzzi® Hot Tub – or thinking of buying one, you’ll find that the SmartTub® system is equipped with a new feature called 'Smart Heat Mode'.  

As the name suggests, it cleverly works out how long it takes to reach the temperature you want, at the time you want and provide you with energy saving information, based on the details you input. This means you won’t be wasting money on the hot tub constantly switching from cold to hot. 

What temperature should I set my hot tub to in summer?  

Hot tubs are not just limited to winter use; they can also be a refreshing way to cool off in the summer. To determine the ideal water temperature for your preference, you can experiment with temperatures, depending how hot your climate is.  

Some people like to cool off at as low as 26°C and it is not recommended to go over 35°C in warmer weather. Finding the perfect temperature involves striking a balance between comfort and safety. 

Expert tip – If a hot tub is hot and struggling to drop in temperature, you may want to open the vents or leave the cover off for a short time. Speak to your hot tub salesperson for specific recommendations to your brand.

Read here to learn how to properly prepare your hot tub for the warmer months. 

What temperature should I set my hot tub to in winter? 

The winter months are a great time to make use of your toasty hot tub! To ensure protection for your hot tub, it is recommended to maintain a steady temperature of around 38°C.

We also recommend to always keep the cover on the hot tub, to prevent heat from escaping when not in use. 

You can learn more about using a hot tub in winter by reading this article. 

Hot tub with cover off in winter

What temperature is too high for a hot tub? 

Typically, the recommended temperature range for hot tubs is between 37.8°C and 40°C. Temperatures above this range can be too hot and can cause health problems such as overheating, dehydration, dizziness, and fainting.  

Extremely high temperatures can also damage or warp the hot tub's components, which can be costly to repair. It is important to always monitor the temperature and adjust it accordingly to prevent any potential dangers. 

What temperature is too low for a hot tub? 

In warmer climates, people might turn down their hot tub temp to as low as 26°C. This is because the heat outside can help keep the water warm enough to be in and cool enough to relax in the heat 


However, if you set the temp too low, you might end up wasting money with nothing to show for it because the water will be too cold to enjoy.  


If you're using your tub for hydrotherapy, a temp that's too low could mean you don't get the full benefits. That's because heat is key for the jets to do their hydrotherapy magic.

Kim Morrison relaxing in a hot tub

What temperature should my hot tub be for kids? 

The supervision of children in hot tubs is crucial. The Centers for Disease Control and Prevention (CDC), advises that children under the age of 5 years, should not use hot tubs. If your child is over 5, the temperature should be lower than usual, at around 35°C. 

What temperature should a hot tub be when pregnant? 

Hot tubs can raise your core body temperature rapidly which can be dangerous to pregnant women. Too high of temperatures could cause fainting or dehydration, so pregnant women should take precautions with using a hot tub, with lower temperatures and less usage. 

We are not medical professionals and the best advice you can get surrounding hot tub use within pregnancy is from your doctor or midwife. They will be able to suggest the correct precautions for each circumstance. 

Read here to explore the risks, precautions and more that come with using a hot tub when pregnant. 

How can I save money when heating my hot tub? 

The most important piece of advice we can give is to invest in a high-quality insulated cover to keep the heat inside the hot tub. This will reduce the amount of heat that is lost to the surrounding environment and will help you save money on your energy bills. 


You can also use a timer to control when your hot tub is heated. Ideally, if possible, you should heat your hot tub during off-peak hours when energy rates are lower.  

Another great money saving method would be to lower the temperature of your hot tub when you’re not using it. You can heat it up again before use, which can help you save money on your energy bills.  

Check out this article to learn more about hot tub insulation and different options on the market, from good to best.

Could SmartTub® save me money when heating my hot tub? 

Apps that connect to your phone, such as SmartTub® can be helpful in saving money in several ways. They can track kWh energy usage and display this in the app, as well as showing you on and off-peak costs. This will vary depending on the brand and product. 

Smart Heat Mode, as mentioned earlier in this article, is a key feature of SmartTub® that helps you helps you estimate the energy savings you'll receive by planning your soak sessions in advance. 

For more details about SmartTub®, we recommend you read this useful article which answers questions such as how much does SmartTub® cost, main features, how it can make you use your hot tub in a more energy efficient way, and more.


Temperature knowledge is a very important element to being a hot tub owner and one that should be taken seriously. Pregnancy, the weather, age, personal preference, health conditions and more can all become factors in determining the exact temperature of your water.  

You can be savvy by using apps and adequate insulation to ensure costs are as low as possible, while still maintaining the perfect temperature for a steamy, relaxing soak on hand whenever is needed. 

If at any point you are concerned about your safety or of others and want some peace of mind, we recommend you speak to a medical professional.  

With these points clarified, you can sit back, relax and soak in all the wonderful benefits of having your hot tub at the perfect water temperature!

For more informative content and answers to common questions that current or potential hot tub owners have, continue to browse through our Learning Hub articles.

Interested in learning more about Jacuzzi® Hot Tubs? Click the button below to explore our extensive range across our three collections.