There’s nothing worse than hopping into a hot tub that’s too hot or too cold. Read on to find out how to get the temperature just right, so you can get back to relaxing.
Finding the ideal hot tub temperature
Safe water temperature is important for everyone, but even more so for vulnerable people. Anyone with underlying health conditions should consult a doctor or medical professional before using a hot tub.
The perfect temperature comes down to personal preference. A good place to start is your body temperature, which on average is 37°C. Most hot tubs will be set at 38°C as standard, which tends to be the most comfortable for bathers to enter. It allows for the temperature to drop, which occurs naturally when people enter the water.
The highest safe hot tub temperature is 40°C. This is the industry agreed maximum, BISHTA (The British and Irish Spa and Hot Tub Association) state that bathing in water above 40°C can be dangerous, posing serious health risks.
Most tubs can be set as low as 26°C which is great for cooling off on a hot summer’s day.
Safe temperatures while pregnant
The NHS advise against using a hot tub while pregnant, as there’s an increased risk of overheating, dehydration, and fainting. Even just 10 minutes of sitting in hot water can raise body temperature higher than 38°C, which poses health risks to you and your baby, so should be avoided while pregnant. Always consult your doctor or midwife if you’re unsure.
Safe temperatures for kids
It’s recommended that children under 5 don’t use hot tubs. If your child is over 5, a slightly lower temperature of 35°C is best because children are less able to regulate their body temperature.
Children should always be supervised when using a hot tub to avoid any injury, and make sure they drink plenty of water to stay hydrated.
Heat-related health risks
Using your hot tub when unwell or if your body temperature exceeds 39°C can cause problems such as:
- Heat exhaustion
- Heat stroke
- Heat rash
- Heat cramps
Prolonged exposure to heat could also aggravate any pre-existing chronic conditions such as respiratory, cerebral, and cardiovascular disease. Always consult a medical professional before using a hot tub if you have any underlying conditions.
How long does a hot tub take to heat up?
It depends on the starting temperature of the water, how efficient your tub is, and the quality of installation.
Most hot tubs will rise between 3 to 6 degrees per hour, taking anywhere between 4 and 20 hours to reach the correct temperature. If you want to speed up the process, leave the thermal cover on so heat can’t escape. The warmer it is outside, the quicker your hot tub will heat up.
The good thing about hot tubs is that they maintain their heat, meaning you only need to wait for your hot tub to heat up if you’re setting it up for the first time, or have just refilled it with fresh water.
Looking to reduce the cost in heating your hot tub? Check out our energy-saving air source heat pumps.
How to change hot tub temperature
Most hot tubs have an electronic control panel that’s used to maintain or adjust the water’s temperature. This will display the current temperature, so you can decide whether you want to increase or decrease it. The buttons on the control panel will be clearly labelled, usually with a + to increase the temperature and a – to decrease it.
Hot tub temperature when not in use
If you’re not going to use your hot tub for a while, avoid turning it off completely and keep it at a lower temperature of around 30°C. If you turn it off completely, it’ll take longer to heat up so it’s less cost-efficient. Make sure you still check the chemicals while tub isn’t in use.
Hot tub temperature in winter
The winter months are when people tend to take full advantage of their hot tub, you can sink into the warm water and watch the steam rise into the cold air. Keeping the temperature at 38°C keeps you warm while protecting your hot tub, as the heat generated prevents your power pack from freezing over. Keep the cover on when you’re not using it, so the heat doesn’t escape. If you're not planning on using your tub over the colder months, consider winterising your hot tub, find out more in our guide. You can also book a hot tub winterising service with us.
Hot tub temperature in summer
Hot tubs are great for cooling off too. Depending on how cool you want the water to be, we recommend experimenting with temperatures between 29 and 35°C to find the most comfortable temperature for you.
If you want the water to cool down quicker, drop the temperature on the control panel then turn on the jets; the circulation of the water will cool it down quicker.
So, there you have it, it’s all about balancing comfort with safety and the perfect temperature tends to be down to personal preference. Looking for a new hot tub heater? Shop our spa heating range here. Enjoying the heat from your hot tub is a great way to unwind after a long day.