Float tanks (sensory deprivation or isolation tanks) offer deep relaxation by eliminating external stimuli while the body floats effortlessly in a highly concentrated Epsom salt solution. This experience promotes mental clarity and physical rest and is generally safe for most healthy adults. However, the sensory-restricted environment and high mineral content require caution for specific populations and medical conditions to ensure safety and maintain facility hygiene.
Chronic Health Conditions Requiring Exclusion
Individuals with certain chronic medical conditions face elevated risks in the isolated environment of a float tank and should seek medical clearance. Uncontrolled seizure disorders, such as epilepsy, are a serious contraindication because a seizure event while face-up in the shallow water poses an immediate risk of aspiration or drowning. The lack of external monitoring or immediate assistance within the tank means a sudden loss of consciousness can become life-threatening before staff can intervene.
Cardiovascular regulation can be affected by the deep relaxation induced by sensory deprivation. People with unstable or severe heart conditions, or those with untreated high or low blood pressure, must consult their physician. The shift in blood flow and heart rate accompanying deep rest could potentially destabilize an already compromised cardiovascular system.
The body’s ability to process minerals is a concern for those with impaired kidney function. Float tanks use Epsom salt (magnesium sulfate), which the body can absorb through the skin. For individuals with kidney disease, particularly severe impairment, the kidneys may struggle to process an increased magnesium load, leading to a dangerous buildup in the bloodstream. Additionally, any person with a permanent medical device that cannot tolerate full body submersion (such as a tracheotomy or certain shunts or pumps) should not enter a float tank.
Acute Physical and Skin Integrity Concerns
Temporary physical states or breaches in skin integrity can make floating uncomfortable and compromise tank hygiene. The high concentration of magnesium sulfate creates a solution far saltier than the ocean, causing an immediate, intense burning sensation on any open wounds, severe cuts, or non-healed surgical incisions. It is advisable to wait until the skin has completely healed, as the salt causes pain and may prevent proper wound closure.
Any contagious skin condition or active infectious disease (such as a severe cold, influenza, or gastroenteritis) requires postponing a float session. Although the water is heavily filtered and sanitized, facility protocols prohibit entry to prevent the spread of illness to other clients and staff. This also includes significant skin conditions like severe eczema flare-ups where the barrier is compromised, or any active fungal infections.
Recent cosmetic treatments involving the skin or hair necessitate a waiting period before entering the tank. Saltwater exposure can be detrimental to the healing process of new tattoos or piercings, causing pain and potentially affecting the ink or the piercing site. Individuals who have recently dyed their hair or applied a spray tan must also wait. The high salt content can strip color from the hair and cause the spray tan to contaminate the tank water, requiring extensive cleaning.
Situational Factors and Psychological Risks
Immediate, temporary conditions and certain psychological factors can make using a float tank unsafe or distressing. Individuals under the influence of alcohol or recreational drugs should not float under any circumstances. These substances impair judgment and coordination, increasing the risk of falling while entering or exiting the tank and preventing the user from safely monitoring themselves or exiting in an emergency.
The sensory deprivation environment, characterized by total darkness and silence, is a profound psychological experience not suitable for everyone. People suffering from severe claustrophobia may experience intense panic or anxiety attacks due to the enclosed nature. While most modern float tanks allow the door to be left ajar, the psychological barrier remains high for those with a serious fear of confined spaces.
In some cases, the absence of external sensory input can exacerbate certain mental health issues. Individuals with a history of severe anxiety, psychosis, or schizophrenia should approach floating with caution, as the lack of stimulation can sometimes lead to disorientation, intensified symptoms, or hallucinations. Furthermore, a user must be able to safely enter and exit the float tank unassisted. The presence of water and salt residue makes the surrounding floor and tank entry point slippery, requiring a degree of personal mobility that may be difficult for some people to manage.