Cold showers: the easiest way in

How to start — in 30 seconds

You don't have to start ice-cold. Shower at your normal warm temperature, then switch to cold for 30 seconds at the end — hands and legs first, then your neck and torso. Keep breathing calmly and deliberately instead of holding your breath. Build up the time over the weeks.

Are cold showers good for you? What's actually backed by evidence

The most noticeable effect is alertness: cold triggers a surge of the neurotransmitter norepinephrine — which explains the "clear, awake" feeling afterward, and unlike caffeine, there's no crash. How strong the surge is depends on the cold: a 2023 fMRI study measured the alertness effect after 5 minutes of full-body immersion at around 20 °C. A short, moving shower is a weaker stimulus than a bath like that — but it delivers a noticeable part of it, with no equipment at all.

That's exactly what makes the cold shower so practical: a short, reliable jolt of energy with no equipment — the easiest way to make cold a daily habit. For what's going on behind it, see what cold does to your body.

How cold does your shower actually get?

A cold shower is never colder than your tap water — that's its natural limit. How cold that is depends on your region and the season: often single digits in winter, much milder in summer. That's actually handy, because even low double-digit temperatures trigger a clear cold response, and colder hits harder — so in many places a winter shower already falls into the effective range. For real ice-cold, you need ice.

How to squeeze out a few more degrees

If your tap water isn't cold enough in summer, there are a few simple tricks to chill the shower down further — all without tools or a plumber:

• Hang ice in the stream. Fill a mesh bag — a laundry or produce bag works — with ice cubes and hang it over the showerhead so the water runs through the ice. It costs almost nothing. Honestly, the effect is limited, because the stream only touches the ice briefly — good for a few degrees, but not real ice-cold.
• Pre-chill the water — this works best. Freeze one or two water bottles overnight and set them in a bucket of water before you shower (or just add ice cubes). At the end of the shower, pour the pre-chilled water over your neck and shoulders. Because you control the contact time, it gets noticeably colder than the stream.
• Use the time of day and the season. The water comes out of the tap coldest in the morning and in the colder months. Let it run briefly at the start to clear the lukewarm standing water out of the pipes.

Ready for more?

Once the cold shower has become routine and you want it much colder, a bathtub with cold water and ice is the next step — about 10–20 kg of ice brings a normal tub down to 10–15 °C. It only gets colder than that in a real ice bath or cold plunge. For how to do it safely and what equipment you need, see the ice bath guide.