The most searched cold plunge question in the UK is also the simplest to answer badly. Forums are full of people bragging about ten minutes at two degrees. That is not a protocol, it is a party trick. Here is what the research and a few thousand mornings actually support.
The short answer
Two to three minutes, at 4 to 10°C, three to five times a week. If you are new, start at 30 to 60 seconds at 12 to 15°C and build up over a month. The total you are aiming for across the week is around 11 minutes, the figure most often cited from Dr Susanna Søberg's work on cold exposure. You can hit that in four short sessions.
Why longer is not better
Almost all of the useful response happens in the first two minutes: the sharp rise in noradrenaline and dopamine, the breathing you have to bring under control, the alertness that lasts for hours afterwards. After that the returns flatten and the risks climb. Past five minutes at very cold temperatures you are mostly training your body to lose heat, which is not the goal, and you start to feel the afterdrop, where your core temperature keeps falling for a while after you get out.
The rule that keeps people consistent: get out while you could still stay in. Numb hands and shivering that will not stop are signs you went too long, not badges.
What temperature?
| Temperature | Who it is for | Time |
|---|---|---|
| 12 to 15°C | Your first two weeks | 30 to 90 seconds |
| 8 to 12°C | Building the habit | 2 minutes |
| 4 to 8°C | The daily ritual for most people | 2 to 3 minutes |
| Below 4°C | Experienced, supervised, occasional | 1 to 2 minutes |
Colder is not a higher score. Four degrees, held steady, is cold enough to get everything the practice offers. That is why a plunge with a chiller matters: a bath of ice starts at two degrees and is nine degrees twenty minutes later. The protocol only works if the water does what you set it to.
A four-week way in
- Week one: 15°C, 45 seconds, three mornings. Breathe out slowly on entry. Do not hold your breath.
- Week two: 12°C, 90 seconds, three or four mornings.
- Week three: 8 to 10°C, two minutes, four mornings.
- Week four: 4 to 8°C, two to three minutes, four or five mornings. This is your routine now.
When in the day?
Morning, for most people. The alertness lasts three to six hours and you want that at your desk, not at bedtime. If you are plunging for training recovery, keep it a few hours away from strength work, for reasons we cover in our piece on the research.
Safety, briefly
Never plunge alone at first. Enter slowly, never dive. Keep your head out until you are experienced. If you have a heart condition, high blood pressure or are pregnant, speak to your GP before you start. Cold water is a strong stimulus, and that is exactly why it works.
Nordrime plunges hold any temperature from 3 to 20°C, round the clock, so the protocol above is a setting, not a chore. See the Fjord.