Cold Plunge.

Cold plunge has gained a large cultural following independent of the cryo industry — partly through Wim Hof, partly through athletic-recovery culture, partly through biohacker podcasts. Cryo studios saw the overlap in customer profile and added plunge tubs as a second offering. For studios, it is a lower-equipment-cost ($8K to $25K for a good tub with chiller) addition that meaningfully increases per-visit revenue. For clients, it is usually cheaper per session than a chamber.

Water conducts heat far more efficiently than air, which means a three-minute plunge at 4 °C delivers a more intense systemic cold exposure than a three-minute chamber session at −100 °C, even though the air temperature sounds more extreme. The subjective experience reflects this — plunges feel much harder than chambers for a given duration. The body's physiological response follows the same general pattern (vasoconstriction, catecholamine release, vagal rebound), but the intensity curve is steeper.

Standard protocol for beginners is 30 to 60 seconds the first time, gradually building to two to six minutes over several sessions. The temperature most studios default to is 4 °C to 10 °C. Going below 4 °C does not improve benefit and meaningfully raises risk of cold shock response — involuntary gasp, reflexive hyperventilation, and (in rare cases) cardiovascular incidents in unscreened clients. Head-out protocols (head stays above water) are universal in studios; full-body submersion is not a studio practice.

Two to six minutes in the water, plus three to five minutes of before-and-after management. First-timers should start at 30 to 60 seconds and build. Total appointment time is 10 to 15 minutes. Sessions longer than six minutes are not better; they just accumulate more discomfort for no additional physiological return and raise hypothermia risk in sensitive clients.

$25 to $70 per session is typical — slightly cheaper than a chamber session because the equipment is cheaper. Package pricing and memberships follow the same pattern as cryo. Many studios now sell a 'chamber + plunge' combo at a small discount, which is the most common combined booking.

What is your water temperature, and how often do you verify it with a calibrated thermometer? How do you sanitize the tub between clients (chlorine, ozone, UV)? Do you screen for cardiovascular conditions before a first plunge? Is an operator present for first-time clients? These are basic hygiene and safety questions — a studio that cannot answer them crisply is not a studio you want for your first plunge.