Cryo, short for cryotherapy, is the use of extreme cold to treat the body. It spans a wide range of applications, from medical procedures that freeze and destroy abnormal tissue to wellness treatments where you stand in a chamber cooled below -100°C (-148°F) for a few minutes. The term covers everything from a dermatologist spraying liquid nitrogen on a wart to an athlete stepping into a full-body cold chamber after a game.
Medical Cryotherapy: Freezing to Heal
The oldest and most established form of cryo is medical cryotherapy, sometimes called cryosurgery or cryoablation. A healthcare provider uses an extremely cold substance, typically liquid nitrogen, liquid nitrous oxide, or argon gas, to freeze and destroy abnormal cells. For skin conditions, this usually means spraying liquid nitrogen directly onto the growth or applying it with a cotton swab. For internal tumors, a thin instrument called a cryoprobe is inserted into the body to deliver the cold precisely to the target tissue.
The list of conditions treated this way is broader than most people realize. Cryosurgery is used for several types of cancer, including basal cell and squamous cell skin cancers, early-stage prostate cancer, liver cancer confined to the liver, certain bone cancers, and non-small cell lung cancer. It also treats precancerous conditions like actinic keratoses (rough skin patches that can become cancerous) and abnormal cervical cells that could develop into cervical cancer. Retinoblastoma, a rare eye cancer in children, is another application.
Whole-Body Cryotherapy
Whole-body cryotherapy (WBC) is the version you’ve likely seen on social media or at wellness studios. It involves stepping into an enclosed chamber or room where the air temperature drops to between -100°C and -140°C (-148°F to -220°F). Sessions last between two and five minutes. You wear minimal clothing, and the facility provides gloves, socks, and slippers to protect your fingers and toes, the areas most vulnerable to frostbite.
The core idea is straightforward: exposing the body to extreme cold triggers a cascade of physiological responses. Tissue temperature drops, which reduces blood flow to the extremities and slows cellular metabolism. Your nervous system reacts to the cold stress, and your body redirects resources to protect vital organs. Once you step out and warm up, blood flow increases again. Proponents believe this cycle reduces inflammation and speeds recovery, though it’s worth noting that current recommendations for session temperature, duration, and frequency are still largely based on anecdotal experience rather than standardized clinical guidelines.
Cryo for Athletic Recovery
Athletes are the most visible users of whole-body cryotherapy. The primary goal is reducing delayed-onset muscle soreness, that deep ache you feel a day or two after intense exercise. Cold exposure lowers the temperature inside the muscle, slowing metabolism and reducing the swelling that occurs when muscle fibers are damaged during hard training.
A large network meta-analysis comparing multiple recovery methods found that cryotherapy ranked highest for relieving muscle soreness and restoring jump ability, a key marker of neuromuscular recovery. It outperformed other popular approaches for those two outcomes specifically, though contrast water therapy (alternating hot and cold water) was better at normalizing blood markers of muscle damage like creatine kinase. In practice, many athletes combine cold exposure with other recovery methods rather than relying on it alone.
Mood and Mental Health Effects
One of the most noticeable effects of cold exposure is the mood shift that follows. This isn’t just perception. When your body hits extremely cold temperatures, it releases endorphins (natural painkillers that promote feelings of well-being) and norepinephrine (a neurotransmitter that increases alertness and energy). The combination produces what many people describe as a rush of clarity and euphoria after a session.
Research from Stanford Lifestyle Medicine found that after just five minutes of cold water immersion at 20°C (68°F), participants reported feeling more active, alert, attentive, proud, and inspired. In longer studies, people who used cold exposure regularly experienced significant decreases in tension, anger, depression, fatigue, and confusion compared to control groups, along with boosts in vigor and self-esteem.
There’s an interesting wrinkle in the long-term picture. The endorphin response may fade over time as your body adapts to the cold. Not everyone experiences it equally, and among those who do, the effect can diminish with repeated sessions. Norepinephrine, on the other hand, continues to rise with each session even after months of regular practice. That sustained norepinephrine boost is likely why regular cold exposure users report lasting improvements in energy and focus rather than just a temporary high.
Cryolipolysis: Cryo for Fat Reduction
Cryolipolysis, marketed under brand names like CoolSculpting, is a cosmetic application of cold that targets fat. It works on a simple biological principle: fat cells are more sensitive to cold than the surrounding skin and muscle cells. When a device applies controlled cooling to an area of the body, the fat cells undergo apoptosis, a form of programmed cell death. Over the following weeks, the body’s immune cells gradually digest and clear away the dead fat cells. The process is slow and subtle. Results typically appear over two to three months as the body processes the destroyed cells.
This is a fundamentally different mechanism from whole-body cryotherapy. Rather than cooling the entire body briefly, cryolipolysis applies sustained, precise cold to specific areas where someone wants to reduce a fat layer. It’s a cosmetic procedure, not a weight-loss method, and it works best on small, targeted areas of stubborn fat.
How Sessions Work for Chronic Conditions
For people with inflammatory conditions like rheumatoid arthritis or ankylosing spondylitis, cryotherapy is typically used as a daily treatment over a concentrated period rather than an occasional visit. Clinical studies on these conditions have used schedules ranging from once daily for two to three weeks to two or three times daily for one week. Sessions generally last two to three minutes at temperatures between -110°C and -140°C, and the cold exposure is paired with physical rehabilitation exercises.
This is a much more intensive approach than the casual once-a-week session someone might do for general wellness. The research consistently pairs cryotherapy with rehab, not as a standalone treatment, suggesting the cold primarily helps by reducing pain and inflammation enough to make physical therapy more effective.
Safety and Who Should Avoid It
Whole-body cryotherapy is generally tolerable for healthy people, but the extreme temperatures involved make it genuinely dangerous for certain groups. Cryotherapy is contraindicated for people with Raynaud’s disease (a condition where small blood vessels in the fingers and toes overreact to cold), peripheral vascular disease, impaired circulation, cold hypersensitivity, or cold-induced hives (urticaria). People with complex regional pain syndrome or open wounds should also avoid it.
The cold causes a spike in blood pressure as your body constricts blood vessels to conserve heat. For someone with uncontrolled cardiovascular issues, this rapid change can be risky. Even for healthy individuals, sessions beyond the recommended two-to-five-minute window increase the risk of frostbite and other cold injuries. The protective gear provided at facilities, particularly the gloves and socks, isn’t optional. Extremities lose heat fastest and are the most common site of cold-related injury during sessions.