If you've ever sat in a sauna in a polyester swimsuit and felt like you were slowly being cooked, you're not alone. There's a better option — and it's not what you'd expect.
Merino wool swimwear performs exceptionally well in saunas, steam rooms, and hot pools. Unlike synthetic fabrics that trap heat and cling as you sweat, merino actively regulates your body temperature — keeping you comfortable whether you're in the heat or moving between hot and cold environments.
It sounds counterintuitive. But once you understand how merino handles heat and moisture, it makes complete sense.
Why merino works in a sauna or spa
Merino is a natural temperature regulator — it works in both directions, keeping you cool when it's warm and warm when it's cool. In a sauna or steam room, that means it manages the heat rather than amplifying it.
The lanolin in merino fibres also resists odour naturally, which matters in a shared spa environment. And because merino absorbs moisture gradually rather than sitting wet on the surface, it doesn't feel heavy or clammy as you move between environments.
How we found out
swimm was designed for the water. Saunas and spas weren't something we'd anticipated.
It was customer reviews that told us otherwise. Our customers were writing in about wearing their swimm pieces in the sauna, the steam room, the spa — and how different it felt to anything they'd worn in those environments before.
A note on care
Rinse in cold water after sauna or hot pool use and lay flat to dry — same as after a swim. The minerals in some thermal pools can affect any fabric over time, so a prompt rinse goes a long way.