Cold Plunge Temperature: How Cold Should an Ice Bath Be?

If you are new to cold plunging, the temperature question comes first. The short answer, from the Cleveland Clinic: beginners should start in water between 50 and 59°F (10 to 15°C), and you should not go below 40°F (4°C). This guide covers what that means in practice, how long to stay in, how to measure the water, and how to get a home tub to the right temperature and keep it there.

How cold should a cold plunge be?

The Cleveland Clinic gives a safe starting range of 50 to 59°F (10 to 15°C) for beginners, and advises against going below 40°F (4°C). It also recommends using a thermometer to confirm the temperature rather than guessing. Cold water that feels bearable to your hand can feel very different when you are in it up to your shoulders.

Cold plunge temperature chart

°F	°C	Notes
59°F	15°C	Top of the beginner range
55°F	12.8°C	Middle of the beginner range
50°F	10°C	Bottom of the beginner range
45°F	7.2°C	Colder than the beginner range
40°F	4.4°C	Do not go below this

To convert: °C = (°F − 32) × 5 ÷ 9.

How long should you stay in?

The same Cleveland Clinic guidance says a session should never go past five minutes, and beginners should stay in for only a minute or two. It suggests starting with one or two plunges a week. Get out straight away if you feel lightheaded or feel discomfort beyond the normal sting of cold water. Do not push through it.

Who should check with a doctor first

The Cleveland Clinic advises talking to a healthcare provider before cold plunging if you have heart disease, high blood pressure, diabetes, peripheral neuropathy, poor circulation, venous stasis or cold agglutinin disease, or if you are pregnant.

How to measure the water

Use a waterproof thermometer that floats or clips to the side of the tub. Measure at the depth you sit, after stirring, because cold water sinks and ice floats. A floating ice bath thermometer with a timer covers both the temperature and your session time.

How to reach your target temperature

With ice

Fill the tub with cold tap water, check the temperature, then add ice and stir until you reach your target. How much ice you need depends on the size of the tub and how warm the tap water is. Our ice bath calculator works it out from your water volume, starting temperature and target. Tap water is much colder in winter than in summer, so the amount changes through the year.

With a chiller

A cold plunge chiller cools and filters the water and holds the temperature you set, so the tub is ready whenever you are and you never buy ice. It suits anyone plunging several times a week.

Keep the cold in

• Use a lid or cover between sessions.
• Keep the tub out of direct sun.
• An insulated tub warms up far more slowly than a thin fold-up tub.

After the plunge

Dry off quickly and put on warm clothes. Many people go back into the sauna to warm up. Read our guide to cold plunging after a sauna, or choose a tub with our cold plunge tub buying guide.

FAQ

What temperature should an ice bath be for beginners?

50 to 59°F (10 to 15°C), according to the Cleveland Clinic. Start at the warmer end and use a thermometer.

Is 40°F too cold for a cold plunge?

The Cleveland Clinic advises not going below 40°F (4°C).

How long should I stay in a 50°F cold plunge?

Beginners should stay in for a minute or two, and no session should go past five minutes.

Source: Cleveland Clinic, What to know about cold plunges. This guide is general information, not medical advice.