A Himalayan salt sauna is a cabin with one wall or a panel of backlit pink salt blocks, sold as an upgrade on infrared cabins. It looks good, it is warm to the touch, and the claims attached to it are considerably larger than anything that has been shown. Separating those is worth doing before paying the premium.
What it actually is
Blocks of rock salt, usually mined in Pakistan, stacked as a decorative wall with lighting behind them. In a sauna they are a heavy, warm, glowing surface. That is the whole of what is physically happening: a wall of salt with a lamp behind it, at cabin temperature.
What is claimed and what is shown
Sellers describe negative ions, air purification and respiratory benefit, borrowing the framing from halotherapy salt rooms. Salt lamps and salt walls are not shown to release meaningful quantities of anything into the air, and salt rooms themselves use aerosolised salt from a machine, which a solid wall does not do. Treat the claims as unsupported.
What it costs you
Money first, since it is a premium option. Then heat, because salt is dense and absorbs energy, so a salt wall lengthens heat-up. Then maintenance: salt is hygroscopic, so blocks in a humid cabin can weep, stain and slowly erode, and the lighting behind them lives in a warm damp cavity. Ask the maker what happens if you pour water in that cabin.
Should you buy it
As a piece of lighting and a surface you like looking at, if the premium is small and you want it, fine. As a health feature, no, and a maker charging heavily for it on that basis is selling something they cannot support. It is the same judgement as the chromotherapy option: pleasant, decorative, not medicine.
Questions people ask about himalayan salt sauna
Does a salt wall purify the air?
There is no competent evidence that a solid salt wall releases anything meaningful into the air. Salt therapy rooms aerosolise salt with a machine, which a wall does not do.
Does it affect the sauna's performance?
Yes, slightly. Salt is dense and absorbs heat, so a salt wall lengthens the heat-up and the heater should be sized with it in mind.
Will the salt degrade?
Salt is hygroscopic, so in a humid cabin blocks can weep and erode over time. Ask the maker what they say about pouring water in that cabin.