I was pleased to see Spa Business focusing on cryotherapy (see SB19/1 p76), but it did not explain the significant differences between direct and indirect cryotherapy.
Direct cryotherapy applies cold nitrogen vapour directly to the body, with the head typically above and external to the chamber.
Indirect cryotherapy uses liquid nitrogen to cool down air so the user is only ever exposed to the super-chilled air and the nitrogen gas is safely ducted away. The user can experience cryotherapy in a fully enclosed chamber and the entire body, including the head, is exposed to extreme cold. This is important because so many of the wellbeing benefits are based on the brain’s response to cold.
There are safety implications to consider too. Direct exposure to nitrogen vapour carries a risk of asphyxiation and cold burns. Many direct cryotherapy systems are not supplied with oxygen monitors and ventilation systems which, while costly, are crucial for safe operation. Gas companies won’t supply liquid nitrogen if installations do not meet stringent safety criteria.
In addition, while overseas manufacturers may seem like a cheaper option at the outset, they can leave customers without any locally-based engineers to deal with maintenance issues. Service agreements should be scrutinised!
Being aware of these issues before making an investment could help spas avoid expensive and potentially harmful mistakes further down the line.