
In trials, cold-water immersion raised inflammation at first, then lowered stress 12 hours later, and a cold-shower trial saw fewer sick days. No average effect on mood. Judge it over the next day, not in the bath. Promising, not proven.
S Evidence: strong. Large trials or many studies, pointing the same way.
P Evidence: promising. Good studies, but small or few. Use it and keep checking.
Cain et al. 2025 (meta-analysis, 11 trials) · Kelly et al. 2021 · Briganti et al. 2023 (review: small, mixed, short-term).
Not medical, legal or financial advice.
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