Whole body cryotherapy involves stepping into a chamber where temperatures plummet to between -100°C and -140°C for a brief period, usually two to four minutes. While marketed as a revitalizing recovery tool, this extreme cold exposure triggers powerful physiological responses that can lead to a range of side effects. Understanding these potential reactions is essential for anyone considering this treatment to distinguish between expected, short-lived sensations and signs of a more serious issue.
Common and Generally Harmful Side Effects
The most frequently reported side effects are temporary and directly linked to the body's immediate reaction to freezing temperatures. These sensations are typically benign and subside within minutes after exiting the chamber as the body gradually returns to its normal temperature.
Intense Cold Sensation: The most immediate experience is a penetrating cold that envelops the body, which can be startling for first-time users.
Skin Redness and Irritation: Superficial blood vessels constrict dramatically, leading to temporary redness, and upon rewarming, the skin might appear flushed or feel itchy.
Tingling and Numbness: Extremities like fingers and toes often go numb during the session as the body prioritizes warming core organs over peripheral areas.
Temporary Fatigue: Some users report feeling tired or lethargic immediately following a session, likely due to the significant energy expended to regulate core temperature.
Cardiovascular and Blood Pressure Considerations
Because cryotherapy forces blood away from the skin and toward the core, it places a notable stress on the cardiovascular system. This physiological shift can trigger acute, short-term changes that warrant caution for specific populations.
The sudden cold causes peripheral vasoconstriction, which temporarily increases blood pressure and heart rate as the heart works harder to pump blood through the narrowed vessels. For most healthy individuals, this is a manageable stressor. However, people with uncontrolled hypertension, heart disease, or a history of stroke should avoid this treatment unless explicitly approved by their cardiologist, as the abrupt spikes in cardiac demand could pose a safety risk.
Respiratory and Sensory Responses
The shock of extreme cold does not only affect the skin and heart; it also triggers distinct reactions in the respiratory and nervous systems. These responses can be uncomfortable but are usually not dangerous for healthy adults.
Many users experience a sharp, involuntary gasp or catch their breath upon entering the chamber due to the sudden chill hitting the chest. Some report a temporary burning or stinging sensation in the airways, particularly if the air is very dry. Furthermore, the vagus nerve can be stimulated by the cold, potentially leading to dizziness or a brief feeling of lightheadedness as the body attempts to regulate its internal systems.
Rare and Serious Risks
While whole body cryotherapy is generally safe when conducted in a professional setting, ignoring safety protocols or having specific pre-existing conditions can lead to more severe complications. Being aware of these rarer risks is vital for ensuring a safe experience.
One of the most serious concerns is frostbite, particularly if the treatment duration is extended or the chamber temperature is improperly regulated. Although the skin is usually protected by clothing, any failure in temperature control can cause ice crystals to form in tissues. Additionally, individuals with certain medical conditions, such as severe anemia, Raynaud's syndrome, or epilepsy, may be at a higher risk of adverse events. Claustrophobia can also be triggered by the confined space of the chamber, leading to significant anxiety during the procedure.
Post-Treatment Headaches and Discomfort
Following a session, some individuals might experience a specific type of headache known as a "cold stimulus headache," which feels similar to a brain freeze. This occurs when the cold penetrates the tissues surrounding the sinuses and the meninges, the protective layers covering the brain.
