How Hot Should a Hot Tub Be?

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A hot tub is the ideal place to soak the tension out of stiff muscles and soothe frayed nerves. It can be a haven of relaxation and rejuvenation you will use every day, calming the mind, releasing built-up stress, and even helping to repair physical strains.  

However, when it comes to enjoying the perfect hot tub experience, you can’t forget about the temperature dial. How hot or mild you keep your hot tub affects not only your comfort and its therapeutic efficiency: setting the wrong temperature also plays a significant role in the longevity of your hot tub. Choosing a setting that’s too hot can even endanger the safety of users, and that’s probably the last thing you want to do.  

Our whole purpose with this blog is to help you make your hot tub as pleasant, safe and easy as possible to use. We are therefore going to explore the best temperature  for your hot tub, some factors that affect how hot your tub should be kept, and a few potential health and maintenance implications you should be aware of.  

Somewhat surprisingly, there’s no single answer to the question: “How hot are hot tubs supposed to be?” So, let’s dive in and discover the secrets to setting the perfect temperature for your hot tub. 

Understanding Hot Tub Temperature Basics 

Chances are that you’ve never really thought about the ideal temperature for your hot tub. You probably think of it as “comfy”, a heat level that’s somewhere between “freezing” and “I boiled myself like a lobster”. 

In this article, we’ll get a lot more specific about how hot your hot tub should be, taking into account your and your guests’ preferences, maintenance considerations, and possible medical effects – both healthful and potentially dangerous. Let’s get down to brass tacks:  

Hot tubs are typically heated to somewhere between 32 °C to 40 °C (90 °F to 104 °F). This may seem like a pretty narrow range compared to, say, a steam room (which is different from a sauna); these can generally be set to anything between 30 °C and 50 °C (86 °F and 122 °F). However, the feeling you’ll get while lounging in your hot tub differs considerably between the maximum and minimum settings. 

The optimal temperature you’ll choose will vary depending on various factors, including your personal preference, age and health conditions, your electric bill and external weather conditions. In some cases, you may have to make a few compromises to make sure all of these are taken into account. Fortunately, it’s not too hard to find the temperature that suits you best for a comfortable and enjoyable hot tub experience. 

Factors to Consider When Setting the Hot Tub Temperature 

Personal Comfort 

The primary consideration when determining the ideal hot tub temperature is how the water feels to you and others. While everyone’s preferences differ, most hot tub users find that a temperature range between 100 °F to 102 °F (37.5° C to 39 °C) provides the perfect balance between warmth and relaxation. However, it’s essential to remember that what feels comfortable to one person may be too hot or too cool for another. It’s therefore recommended to experiment with different temperatures to find your sweet spot. 

Health and Safety 

Product warning labels and workplace health-and-safety rules have a reputation, often deservedly, for being somewhat silly at times. Your hot tub’s user manual probably cautions you against using electric appliances in or near the water – while this is sensible enough, it’s also not the kind of thing you should have to mention to adults. Sometimes, though, these warnings are worth listening to and not necessarily intuitive. 

Remember, too, that when it comes to hot tub temperature, it’s not only your health and safety that’s at stake but that of everyone who may end up using it. The United States Consumer Product Safety Commission (CPSC) advises keeping the temperature at or below 40 °C (104 °F) for adults. This is slightly warmer than your body’s internal temperature, which means that heat will actually be flowing into rather than out of you at this level. 

Temperatures above this threshold can pose a risk of heatstroke, especially during prolonged use. How hot are hot tubs in practice? When does a typical person feel like the temperature is too high? For a safe and comfortable soak, most healthy adults prefer setting their hot tub temperature between 37.5 °C and 39 °C (100°F and 102°F), i.e. just short of the danger zone.  

You may want to err on the side of caution when you have visitors, though. It is important to note that individuals with underlying health conditions, such as heart problems or pregnancy, should consult with a medical professional before using a hot tub. Since a guest may be too embarrassed to tell you about their high blood pressure (and could even be unaware of the danger themselves), turning the knob down a degree or two could save you a whole lot of trouble. 

Age Considerations 

It goes without saying that a hot tub is best enjoyed in the company of friends or family members. What you may not realize, though, is that deciding on the perfect temperature isn’t a democratic process: a hot tub’s temperature should be no hotter than is safe and comfortable for everyone. 

It’s crucial to consider the age of everybody using the tub. Children and older adults have different temperature tolerances due to their varying abilities to regulate body temperature; kids may also not realise when they’re pushing their limits.  

When children are sharing the water, it’s recommended to keep the hot tub temperature around 35 °C (95 °F) or lower to prevent dehydration and other problems from cropping up. Generally speaking, older adults also require a lower temperature, especially if they suffer from pre-existing health conditions that affect their body’s ability to tolerate excessive heat.  

It’s always best to adjust the temperature of your hot tub to a level that takes the  comfort and safety of all hot tub users into account. While a cooler temperature may not be perfect for you, a too-high setting can be actively miserable for others without you even realising it. 

How Hot Are Hot Tubs Supposed to Be: Finding Your Ideal Hot Tub Temperature 

By now, you have a better understanding of some things to consider when setting your hot tub’s temperature. When all is said and done, though, the best temperature is a question of personal preference – both yours and that of others who may want to use the tub. Let’s take a moment to talk about finding your ideal heat level. 

Start Low, Increase Gradually  

In the excitement of setting up your hot tub for the first time, it’s easy to get carried away and crank up the thermostat to its maximum. However, especially if you’re not used to soaking, it’s advisable to start with a lower temperature and gradually increase it. The same applies when you’re adjusting the temperature after a water change; it may be possible to get just as much satisfaction from a cooler hot tub. 

It’s recommended that you begin by setting the heating controls to somewhere around 36.7 °C to 37.2 °C (98 °F to 99°F). You may have to wait several hours for the water to actually reach this temperature. 

As you enjoy your soak, pay attention to how your body responds to the heat. If you feel the need to get out or sit on the cooling step after a few minutes, you have to acknowledge that the water temperature is too high for your comfort (and, in all likelihood, that of others).  

If, on the other hand, you feel that more heat is needed, increase the temperature only gradually. Before long, you’ll find the sweet spot: relaxing yet invigorating, leaving you feeling restored without the tiredness that comes from boosting the heat beyond what your body can easily handle. 

Consider External Factors 

While personal preferences are the most important consideration when determining the hot tub temperature that’s right for you, it’s important to not ignore external factors. You shouldn’t tie your comfort to a particular number; rather, you will find that your favourite setting changes throughout the year. 

Weather conditions, meaning hot summers and cold winters, can impact your hot tub experience. During the hot months of May through July, it may be a good idea to lower the temperature slightly. This will provide a refreshing escape from the heat your body will have become accustomed to.  

Conversely, when the trees have lost their leaves and the weather forecast is threatening snow, a slightly higher temperature can help combat the chill and provide a cosy retreat from the winter cold.  

You can optimize your comfort and enjoyment by experimenting and fiddling around with the thermostat dial rather than keeping it at some “optimum” temperature that may be months out of date. If you’ve recently started working out, for instance, a warmer hot tub may help draw the pain from sore muscles. 

Consult With Hot Tub Professionals 

How hot should a hot tub be to provide you with the greatest possible pleasure? This may seem like a simple question, but we shouldn’t ignore the various influences that end up determining what we think we like. It’s a little like the toddler who hates broccoli without ever having tried it, or the woman who wears uncomfortable high heels just because they’re fashionable. 

If you’re unsure about the best hot tub temperature for your specific needs, asking the people who sell, install, maintain and clean them for a living can provide valuable insights and guidance. As you would expect, hot tub dealers and manufacturers have extensive knowledge and experience in their field and spend a lot of time thinking about all aspects of their work, including helping customers find the optimal temperature settings.  

When giving you their expert opinion, they will probably consider factors such as your location, climate, and personal preferences. Don’t hesitate to reach out to hot tub professionals for expert advice tailored to your unique circumstances. This, in fact, is one of the best arguments for buying your hot tub and related supplies from a brick-and-mortar retailer rather than online. 

The Impact of Hot Tub Temperature on Utility Costs 

Assuming that you don’t rent one for a season or even a single event, purchasing a high-quality hot tub can cost a pretty penny. That doesn’t mean that your wallet can breathe a sigh of relief once it’s installed, though: there are certain ongoing costs you need to budget for, including electricity or gas use. 

When setting your hot tub’s temperature dial, it’s important to consider the impact this choice will have on your monthly utility costs. While how much your electric bill will increase depends on various factors, you can cushion the blow somewhat. One option is simply to choose a lower temperature, another is to invest in an insulated and well-fitted hot tub cover, but you should also think of future expenses when you’re selecting your new hot tub in the first place. 

Modern hot tubs are designed with energy efficiency in mind, but all of them aren’t exactly equal in this regard. You’ll need to take a look at the specifications for each model and think about how you plan to use it. If you’re going to be busy in the coming month, for instance, with little time to spare for soaking, it may be best to turn the heating element off completely for the time being. 

Most Hot Spring Spas products, for example, are certified according to the California Energy Commission’s (CEC) guidelines, one body which has set standards for energy-efficient hot tubs. Other, similar bodies exist and their seals of approval are worth looking out for. Your utility bills are certainly going to rise once you own a hot tub, but you can take steps to keep this under control. The simplest, of course, is simply to turn down its temperature setting to a lower level. 

Maintaining the Hot Tub Temperature 

Speaking of energy efficiency, it’s generally better to pick an ideal hot tub temperature and stick to it consistently. Especially if you soak regularly or want to be able to plunge in at a moment’s notice, this makes for the most satisfying and energy-efficient experience.  

Hot Spring Spas, one of my favourite hot tub manufacturers due to their advanced features and extras, offer insulated cabinets, custom-fitted covers, and energy-efficient circulation pumps. These all work together to maintain a steady temperature while also conserving energy.  

Even if you own a less energy-efficient kind of hot tub, there’s probably still something you can do to keep the water temperature constant without spending more on utilities. For example, properly sealing your hot tub when it’s not in use and figuring out how to utilise the energy-saving features of your specific model can easily save you ten pounds or more each month. This may not seem like much, but it adds up really quickly. 

From a maintenance perspective, too, it’s far better to maintain a constant hot tub temperature at whatever heat level you find most comfortable. Doing this means that your hot tub’s heating element doesn’t have to be switched on for long periods at a time, reducing wear and tear and increasing its lifespan. In addition, allowing your hot tub’s temperature to see-saw can contribute to cloudy water, increased limescale deposits, and more algae growth. 

Of course, it may not be important to you that your hot tub is always ready to provide a nice soak at your desired temperature. If you only use it once in a while, setting it to a lower temperature most of the time may work out cheaper. It’s best to consult your local hot tub expert on these kinds of questions about energy usage. 

Frequently Asked Questions About Hot Tub Temperature 

Assuming you’ve read this far, you probably have a whole new understanding of the question of how hot a hot tub should be. There are a couple of more specific questions I run across now and then, though, so it seems appropriate to include the answers here. 

Q: What temperature is best for hydrotherapy and arthritis relief? 

A: Hot tubs can provide valuable relief for individuals with arthritis and other joint-related issues without relying on medication and having to accept the possible side effects. Immersing yourself in hot water improves blood flow, promotes joint flexibility, and helps relieve pain. To experience the benefits of hydrotherapy and alleviate arthritis pain, it’s recommended that you set your hot tub temperature around 37.8 °C (100 °F) initially and then adjust it upwards in small increments, but not past the point of discomfort.  

Q: Can a hot tub be used to cool off? 

A: While hot tubs are generally expected to live up to the “hot” part of their name, they can also be used to cool off during hot summer months. By switching off the heating element, you’ll reduce the hot tub’s temperature to ambient, meaning below average body temperature, like a swimming pool. Additionally, advanced systems like Hot Spring Spa’s CoolZone™ technology allow for quick temperature adjustments, enabling you to cool off during the day, then enjoy a comfortable hot soak later in the evening. 

Q: How long does it take for a hot tub to warm up? 

A: The time it takes for a hot tub to reach the temperature you set it to can vary depending on several factors, including the initial water temperature, the efficiency of your hot tub’s heating system, and the quality of your installation. The weather also plays a role, as warmer ambient temperatures generally mean faster heating. On average, hot tubs can rise in temperature by 1.7 to 3.3 degrees Celcius (3 to 6 degrees Fahrenheit) per hour. In other words, it can take anywhere from 4 to 20 hours for your hot tub to get properly hot. You can speed up this process by keeping the hot tub cover on to prevent heat from being lost to the atmosphere. 

Position Yourself for Hot Tub Success 

Almost any gadget or appliance you can buy – a car, a computer, and yes, a hot tub – requires you to learn a little in order to get the most out of it. By now, knowing and understanding a little more about the factors that influence the ideal hot tub temperature, you can improve your and other users’ comfort significantly. 

At the end of the day, the best temperature for a hot tub is a subjective matter that depends on personal preferences, different people’s perceived comfort and tolerance for heat, health and safety considerations, and external factors like the weather. You’ll also want to keep energy efficiency and the potential impact on your monthly utility bills in mind. If you’re having trouble juggling all of these factors, consider consulting a hot tub professional; otherwise, start your water off on the cool end of the recommended temperature range and increase the thermostat setting only gradually.  Doing this carefully and intelligently means creating a relaxing and rejuvenating oasis right in your own back garden. Whether you’re looking for hydrotherapy, arthritis relief, or simply a place to unwind, setting the perfect temperature means getting the most out of your hot tub investment, ensuring that you emerge refreshed and ready to embrace life’s challenges.