Have you ever wondered if you could make the whole hot tub experience even better by getting the water in your hot tub to the optimum temperature? I decided to do some research into the best hot tub water temperature in the quest for ultimate hot tub pleasure!
So, what temperature should the water be in my hot tub? Most hot tubs come with a factory setting of 38 degrees C. The maximum safe temperature for a hot tub is 40 degrees C and most people enjoy the water between 36 and 39 degrees C.
In many ways, it comes down to personal preference and a bit of experimentation. However, there are some important safety and health considerations to bear in mind as well.
Finding the ideal hot tub temperature
37 degrees C is a good starting point, not surprisingly this is also most people’s body temperature, so it’s a comfortable match! However, people’s body temperatures can vary a little from person to person and also depending on the time of day.
Women apparently like it hotter, maybe up to 38/39 degrees as they tend to feel the cold more. Men also have a larger muscle mass which accounts for up to 25% more heat output. Therefore men often prefer it a little cooler.
There’s also no reason why you shouldn’t have the hot tub a little cooler in the summer months and a little warmer in winter. It’s all down to personal preference and a bit of experimentation.
Health and safety considerations
Your hot tub should be restricted to a maximum temperature of 40 degrees C. It’s considered that this is the maximum safe temperature although it’s not recommended to use the hot tub at this temperature. Excessive heating can cause heart attack, heat stroke, brain damage, and even death.
Similarly, you should be very careful about being in a hot tub whilst pregnant. It can take less than 10 minutes to raise your core temperature to a level where it is considered unsafe for the fetus. Having a hot bath can be a good alternative. Unlike in the hot tub, the water will gradually cool whilst you are in it. Also, you won’t be fully immersed helping to keep your core temperature cooler.
People with heart conditions and high blood pressure should also seek professional advice before using a hot tub. Small children are also less able to regulate their body temperature and so should only be allowed in the hot tub for five minutes at a time.
How do I set the water temperature in my hot tub?
Most hot tubs will have a very clear temperature control. This will be very different depending on the model and installation. Some hot tubs have a control on the side, others may have them mounted on the wall nearby, others again might have a digital remote control and simpler inflatable hot tubs will have a simple control on top of the pump.
It can also be a good idea to invest in a hot tub thermometer. These will happily float around with you and will give an extremely accurate reading of the temperature. You might find that the thermometer reading won’t quite match the reading on the temperature control.
This is fine as the water circulates around and might be slightly different in temperature in one part of the hot tub to another. If the two readings are a long way apart it may mean that your hot tub thermostat if faulty and a replacement might be needed.
This thermometer from Amazon is great or you might like to try a slightly more high tech one with an app like this.
Should I keep the temperature on all the time?
Hot tubs are designed to be kept on all the time. This means that the temperature stays constant. The main reason for this is that it takes a lot of electricity to heat up the water to the correct temperature (often many hours). It’s simply not economical to do this every time you want to use the hot tub. Over time, it takes much less electricity to simply maintain the temperature.
You will often find that the better quality the hot tub is the less energy it will use to retain it’s heat. Good quality hot tubs will be thoroughly insulated and have high-quality covers to keep the heat in. Cheaper models leak heat and can often use more energy just to keep hot.
However, it does make sense to switch the hot tub off if you know you won’t be using it for several days. Maybe you will be away on holiday or you know that you won’t use it over the winter for example. In this case, correct drainage and storage (particularly for a freezing winter) is important.
Does the temperature effect how clear the water stays in my hot tub?
Unfortunately, the perfect temperature you enjoy in your hot tub is also a perfect temperature for bacteria to breed and multiply. When you factor in the fact that you will only periodically drain and change the water you can see that there are a huge number of potential problems.
One of the main symptoms of poorly kept water will be that it is discolored and smell bad. Obviously, this isn’t great for encouraging luxurious relaxation and it can also be bad for your health. Warm water encourages your pores to open, bacteria-ridden water can enter and be responsible for all sorts of skin issues and even urinary tract infections.
Poor quality water can also have an adverse effect on the hot tub itself leading to staining and unpleasant smells – not nice!
Luckily there is a solution to the problem.
It’s really important that you add the correct chemicals to your hot tub and that you regularly check and top up. I think it sounds a bit worrying to think that you are essentially bathing in a hot tank of chemical but, as long as you follow the instructions there’s nothing to worry about. Correctly used the chemicals will keep the water clear and healthy and you will be able to enjoy a fresh and sweet smelling hot tub at any time!
This started kit contains all you need and is a good price on Amazon.
What’s the minimum temperature for my hot tub?
You can, of course, keep your hot tub full of water and not have the heating on at all. In this case, it would just be a “cold tub” which might be perfect if you live in a really hot climate for cooling off. If you leave the hot tub full of cold water in the winter, however, there is a real risk of the water freezing and damaging the hot tub.
To avoid this, either completely empty the hot tub in winter or keep it at a reasonable temperature. Some hot tubs automatically switch on the jest once the temperature gets to near freezing in an attempt to keep the water moving and avoid freezing.
There are advantages to keeping the water at a lower temperature. In the high 20 degree C to low 30’s the tub will be roughly at the same temperature as a swimming pool. This can be a much safer temperature for pregnant women and children as well as costing less to keep hot. The chemicals will work just the same and the water will remain clear.
What’s the most efficient way to keep your hot tub at temperature?
The best way to keep your hot tub at the correct temperature over a period of time is to invest in a good quality cover. Not only will the cover prevent debris from flying into the hot tub it will greatly help to keep the warmth in and the cold out. Over time a quality cover will easily pay for itself in saved electricity and is a wise investment.
Related questions
Can I use the hot tub with cold water? There’s no reason why not and, if you live in a very hot climate this might be a good idea. The water doesn’t have to be stone cold but you could keep the hot tub water temperature below body temperature ie 37 degrees C for a cooling effect. You might miss out on the deep relaxing hydrotherapy aspects of the hot tub experience though!
How much does it cost to keep a hot tub at temperature for a month? Broadly speaking between $30 – $40 or 40 – 50 UK pounds per month in electricity but this does depend on the size of the hot tub, the ambient air temperature, how often the hot tub is used and the quality of the hot tub’s insulation.
Andrew Hind
This post was created by Andrew. Enjoyer of hot tub soaking, fine cheese, music and photography.