Almost nobody gives up cold plunging because of their chest. They give up because their hands hurt so much they cannot think, or because they stepped out onto frozen grass, or because the water turned green in week two and they quietly stopped filling it. Every one of those is solvable, and none of them requires being tougher.
Start with your hands and feet, not the tub
Your extremities have the most nerve endings and the least insulating tissue. They hurt first, hardest, and loudest, and they are what makes the first minute feel unbearable. Three-millimetre neoprene gloves and booties take that specific pain off the table and let you actually notice how the rest of your body feels. This is not cheating. It is the difference between a habit and a story about that one time you tried it.
A merino beanie helps too, for the simple reason that keeping your head dry and warm makes staying in significantly easier.
How cold, and for how long
Anything from 10 to 15 °C is genuinely cold water and plenty for a beginner. Below 5 °C is not more virtuous, it is just shorter. Two to three minutes is a normal session. Under a minute still counts.
Get a floating thermometer before you get anything else. Water that feels "freezing" is often 12 °C, and knowing the actual number stops you either overestimating yourself or quietly avoiding it.
The breathing is the whole skill
When you get in, your body will try to gasp. That reflex is the entire difficulty of cold water, and it lasts about thirty seconds. The technique is boring and it works: get in slowly, breathe out longer than you breathe in, and do not talk for the first half minute. Once your breathing is steady, the rest of the time is easy in a way that is hard to believe from the outside.
A three-minute sand timer beats a phone. You will not check a timer every twenty seconds the way you check a screen.
Getting in and out without incident
Wet grass, wet decking and bare feet are how people hurt themselves — not the cold. A non-slip step and a mat to stand on when you get out solve most of it. Have your robe or changing poncho within arm's reach before you get in, not in the house.
Keeping the water usable
This is the unglamorous part that decides whether you are still doing this in three months. Cover the tub between sessions — an insulated lid keeps the cold you paid for and keeps leaves and insects out. Skim it with a net every few days. Change the water when it starts to look like it needs changing, which in cool weather with a cover is far less often than you would think.
After, do nothing warm for a while
Resist the hot shower. Let your body rewarm itself — put on layers, move around gently, drink something warm. The slow rewarm is where a lot of the pleasant afterglow comes from, and jumping straight into hot water throws it away.
Contrast: heat then cold
If you have a sauna, alternating is the whole point. Heat for fifteen minutes, cold for two, rest for fifteen, repeat. Always finish on cold, and always give yourself a proper rest at the end. See our sauna essentials for the hot half.
When not to
Never plunge alone in open water. If you have a heart condition, high blood pressure, or are pregnant, talk to a doctor before starting — cold water puts real, sudden load on the cardiovascular system and this is a reasonable thing to ask about rather than assume.