Cryotherapy (whole-body cold chamber)

What the cold chamber is and how it works

A whole-body cold chamber cools dry air to temperatures below minus 100 degrees. You go in for a few minutes, and the whole body, including the head, is exposed to the cold. Because air conducts heat much less well than water, it is mainly the skin that cools down, whereas an ice bath cools the body more deeply. We cover ice bathing and sauna on a separate page: Sauna & cold (hormesis).

This must be distinguished from the cryosauna, a cabin from which the head sticks out and which is cooled by evaporated nitrogen. The two procedures are often confused, including in studies and warnings, although they differ in technology and risks.

What happens in the body has partly been measured. In a Finnish study, noradrenaline rose two- to threefold with every session, even after twelve weeks of regular cold exposure, while cortisol and the inflammatory messengers in the blood of healthy women did not rise. Immediately after three minutes in the chamber, healthy men tolerated more pressure before it became painful. This short-term pain dampening is the most plausible pathway of action for use in rheumatism and muscle pain.

What the studies show

Leppäluoto 2008 — hormones with regular cold exposure

Ten healthy women went into a chamber at minus 110 degrees for two minutes three times a week for twelve weeks; a second group bathed in ice-cold water. Noradrenaline rose two- to threefold after every session, and this remained so throughout the twelve weeks. ACTH and cortisol did not rise, and the inflammatory messengers IL-1-beta, IL-6 and TNF-alpha did not change. A small study without a clinical endpoint.

Tomschi 2025 — pain threshold, randomized crossover study

24 healthy men spent three minutes at minus 87 degrees once and three minutes at room temperature once. After the cold, the pressure pain threshold rose on average from 77.0 to 89.6 newtons per square centimeter and was still 80.8 after 30 minutes; after the control session nothing changed. 82.6 percent showed pain dampening. What was measured was an acute effect in healthy people, not a treatment of pain.

Klemm 2022 — rheumatoid arthritis

Patients with active rheumatoid arthritis received, during a 16-day inpatient rheumatology treatment, either six additional cold sessions at minus 130 degrees for three minutes each or none. 56 patients were analyzed, 31 with and 25 without cold. On the pain scale from 0 to 10, the score fell 1.31 points more in the cold group (p = 0.002), and after twelve weeks it was still below the baseline value. Disease activity and function improved directly after treatment, but no longer significantly after twelve weeks. 18 of 31 had reduced or stopped painkillers. Single-blinded, without sham treatment.

Cochrane 2015 — muscle soreness after exercise

Four randomized laboratory studies with 64 mostly young, male, physically active participants. One hour after exercise, muscle soreness was lower after cold; at 24, 48 and 72 hours, the confidence intervals also included no difference or an advantage for the control. The evidence was rated as very low for all endpoints, and no study specifically recorded side effects.

Wilson 2018 — marathon

31 endurance-trained men were randomly given a cold-water bath, the cold chamber or a placebo after a marathon. Neither form of cold improved functional recovery or perceived exertion more than the placebo, and for muscle function the chamber performed worse than the cold-water bath. The authors suspect that expectation and the placebo effect explain a large part of the effect of cold on recovery.

Karppinen 2025 — weight loss

19 adults with obesity took part in a twelve-month weight-loss program, 10 of them additionally in 28 cold sessions at minus 110 degrees during the first five months. Weight loss was 11.9 versus 11.5 percent after five months and 9.9 versus 8.0 percent after twelve months, with no significant difference. Brown adipose tissue and energy expenditure did not change more either. Fasting blood glucose and LDL cholesterol fell somewhat more after five months; this needs to be confirmed in larger studies.

Doets 2021 — mental health complaints, meta-analysis

Ten studies, six of them controlled, with a total of 294 people treated. Compared with control groups, there was a moderate effect (Hedges g 0.76), especially for depressive symptoms, with very heterogeneous studies. The authors speak of preliminary evidence for complementary use and call for larger randomized studies.

Where the data stop

Most studies are small, and a true sham treatment is difficult: anyone standing in minus 110 degrees knows it. Where a placebo was used, as after the marathon, little of the advantage remained. Temperature, duration and number of sessions differ greatly between studies, and parts of the literature mix up the chamber and the cryosauna.

For the most heavily advertised goals, the data are missing. For weight loss, the chamber did not help in a controlled twelve-month study, and skin rejuvenation or longevity do not appear as endpoints at all in the studies and reviews evaluated here. The positive meta-analysis on mood is based on a few small studies. Whether regular cold exposure over years has any measurable health benefit has not been studied by anyone.

Status, approval and legal

The cold chamber is not a medicine and does not require an efficacy approval, so there is no officially reviewed indication. In Germany it is used in rheumatology clinics, for example as part of inpatient multimodal treatment as in the study from Bad Nauheim. The G-BA’s Remedies Directive (Heilmittel-Richtlinie) recognizes cold therapy with cold air or cold gas only as a supplementary measure together with physiotherapy, manual therapy or similar treatments; it does not mention a whole-body cold chamber. Offers in studios and sports centers aim at well-being and recovery, not at a recognized indication.

Safety

An international review in 2023 found only 16 documented incidents in the literature, from five case reports and two studies. Most were mild, such as headache, dizziness, persistent shivering, a rise in blood pressure or hives. Individual case reports describe serious events such as a brain hemorrhage or an aortic dissection, for which a connection is considered likely; the person with the aortic dissection had known high blood pressure. Cold burns have mainly been reported from cryosaunas with liquid nitrogen.

The low number does not mean that safety is well studied: many studies did not record side effects systematically at all. In 2025 a European expert group compiled contraindications, including uncontrolled high blood pressure, unstable heart disease, recent heart attack, Raynaud’s syndrome, cold intolerance, acute infections and pregnancy. If you have a cardiovascular disease, clarify its use with a doctor beforehand.

Sources

• Costello et al., Cochrane Database Syst Rev 2015 (muscle soreness after exercise)
• Wilson et al., Eur J Appl Physiol 2018 (marathon, placebo comparison)
• Klemm et al., Clin Exp Rheumatol 2022 (rheumatoid arthritis, RCT)
• Karppinen et al., Obesity 2025 (weight loss, controlled study)
• Doets et al., Complement Ther Med 2021 (mental health complaints, meta-analysis)
• Leppäluoto et al., Scand J Clin Lab Invest 2008 (noradrenaline, hormones)
• Tomschi et al., Eur J Pain 2025 (pain threshold, crossover study)
• Legrand et al., Eur J Med Res 2023 (safety, review)
• Capodaglio et al., Front Rehabil Sci 2025 (contraindications, expert consensus)
• G-BA, Remedies Directive (Heilmittel-Richtlinie), version of October 29, 2024 (§ 24 thermotherapy)