Whole Body Cryotherapy: Procedure, Safety Profile, and Contraindications

What is established

Whole body cryotherapy (WBC) is a standardized procedure in which a person, wearing minimal clothing plus gloves, socks and foot coverings to protect extremities, stands in a chamber cooled with refrigerated air or nitrogen vapor to very low temperatures for a short period, typically on the order of two to three minutes. The procedure, its equipment, and its basic delivery parameters are well described in the international literature, and an expert working group operating under the International Institute of Refrigeration has published a position paper defining how it should be screened for and delivered.[2]

That position paper is explicit that WBC is not a walk-in service without prior assessment. It states that medical screening is mandatory before a person receives whole body cryotherapy, and it sets out a structured list of temporary and permanent contraindications that a supervising clinician is expected to check before every course of sessions, not just before the first one.[2]

What the adverse-event evidence actually shows

A 2023 scoping review conducted by an international consortium searched the literature for documented safety events associated with WBC and cryostimulation. It identified 16 documented adverse events across the available reports, drawn from a mix of five case reports and two randomized controlled trials. Most of these were consistent with known cold-exposure effects, such as skin reactions.[1]

The same review also documented a small number of rare but serious events reported in case literature: intracerebral hemorrhage, Moyamoya syndrome, aortic dissection, and transient global amnesia. In the reports available, these serious events occurred predominantly in individuals who already had pre-existing vascular or cardiac risk factors, which is consistent with cold exposure acting as a physiological stressor on an already vulnerable system rather than as an independent cause of disease.[1]

The review's authors were themselves clear about the limits of this evidence. Serious-event data came from isolated case reports, not from controlled studies designed to measure incidence, and case reports cannot establish how common these events actually are or prove that cryotherapy caused them rather than coincided with them. The honest reading is that serious harm appears rare and appears concentrated in people with prior risk, not that the true rate is known.[1]

The nuance that matters: screening is what makes the risk profile acceptable

The trap in reading WBC safety literature is to treat the small number of serious case reports as either proof the procedure is dangerous or, in the opposite direction, as rare curiosities that can be waved off. Neither reading matches what the two source documents actually argue. Read together, they describe a procedure whose overall risk is low specifically because the people who could be harmed by it can be identified in advance through screening, and the events that were reported occurred in the population screening is designed to exclude.[1][2]

What remains uncertain

The true incidence of serious adverse events cannot be established from the currently published evidence. Case reports, by design, capture events that happened, not events that did not, so there is no reliable denominator and no way to calculate a real-world rate of harm per session or per person. Longer-term or larger prospective safety registries covering broad commercial and clinical use are not yet part of the published record described in these sources.[1]

It is also not established that any single contraindication list is universally agreed in every detail. The 2025 position paper represents a Delphi-based expert consensus among 28 European specialists, which is a rigorous way to build agreement where controlled trial data is limited, but it is still a consensus document rather than a result derived from primary outcome trials.[2]

What this means for you

AION treats whole body cryotherapy as a procedure with a defined and generally favorable safety profile, provided the screening step that the literature ties that safety record to is actually performed. That means a physician reviews cardiovascular, neurological and other relevant history before any course begins, checks it against the documented contraindications, and makes an individual decision rather than defaulting every visitor into the chamber.[2]

It also means AION does not present the rare serious events in the case-report literature as either irrelevant or as evidence the procedure is broadly unsafe. They are read for what they are: a signal that pre-existing vascular and cardiac risk factors are the relevant thing to screen for, and that screening is exactly what shapes your eligibility, not a fixed protocol applied to everyone.[1][2]