The claim: Cold plunges and cold showers improve your health
Cold plunges.
A 2025 systematic review of 11 randomised trials with 3,177 people, mostly testing single sessions.
Evidence level 2 of 5: reviews of randomised trials. What this means
There are real short-term effects on stress, but almost nothing on long-term health. Try a cold shower before you buy a tub.
- Evidence
- Limited: 11 small trials, mostly single sessions, mostly men
- Cost
- Free (a cold shower) to thousands (a plunge tub)
- Watch for
- Cold water raises inflammation markers in the first hour; long-term effects are unknown
What it is
Immersing your body in cold water, from a cold shower to an ice bath or a dedicated plunge tub, usually for a few minutes at a time.
What the research found
- A 2025 systematic review in PLOS ONE pooled 11 randomised trials with 3,177 participants.
- Stress was significantly lower 12 hours after cold-water immersion, but not at any other time point measured.
- Inflammation markers rose immediately and an hour after immersion: a short-term stress response, not a long-term benefit.
- One large trial found cold showers were linked to 29% less sickness absence from work, with no change in the number of days people were ill.
- A small quality-of-life improvement at 30 days had disappeared by 90 days.
- The authors flag few trials, small samples and little diversity: only one study included women, and most tested a single session.
Where this evidence sits
- 1Guidelines and expert position statements
- 2Reviews of randomised trialsThis check
- 3Large long-term studies of people
- 4Small or short human trials
- 5Animal and lab studies
The bottom line
Cold exposure does something, and many people like how it feels. But the evidence for lasting health benefits is thin. If you want to try it, a cold shower costs nothing. A plunge tub is a lifestyle purchase, not a longevity one.
Sources
- Effects of cold-water immersion on health and wellbeing: A systematic review and meta-analysis — Cain et al., PLOS ONE, 2025
Last reviewed 10 October 2026. Ratings change when the evidence does. This is general information, not medical advice: talk to your doctor before changing medication or treatment.