Sauna ready

What to wear in the heat and why 

it matters

Written by Kristy Ovens  20 August , 2026


Yes, you wear swimwear

In most Australian public and communal saunas, swimwear is required. Nude sauna use is common in parts of Europe but rare here outside private or clearly designated venues. 

 

Most venues also ask you to sit on a towel regardless of what you're wearing. Its a hygiene standard, not a suggestion.

 

What you wear matters more than most people realise. A traditional Finnish sauna runs between 70°C and 100°C. Infrared sits lower, around 45°C to 60°C. Neither will melt a quality swimsuit, but both will find its weaknesses.

Nylon vs Polyester

Not all swimwear handles heat the same way. Nylon holds its shape and colour through repeated heat and moisture cycling far better than polyester blends, which pill and hold odour. 

 

It also dries faster, which matters when you're moving between sauna, plunge and shower in the space of an hour.

A few things to leave at home:

  • Padding. Removable cups shift, hold water and take hours to dry
  • Metal. Rings, clasps and underwire get genuinely hot
  • Anything you adjust. If you're fussing with it, you're not in the ritual
  • A single suit, if you're doing multiple rounds — bring a second

Sun Kits uses ECONYL® regenerated nylon for exactly this reason. It performs like premium virgin nylon, without the virgin petroleum.

What touches your skin at 80°C matters

This is the part most people never think about. Heat opens your pores and increases skin absorp, so what sits against your skin in a sauna matters more than it does at the beach. 

 

Conventional textile dyes can carry azo compounds, heavy metals and formaldehyde-based finishes.

 

OEKO-TEX® STANDARD 100 certification tests finished fabric for a long list of harmful substances, at limits set well below regulatory minimums. It is the clearest independent signal available that what's touching your skin has been tested. 

 

Every Sun Kits fixed colour swimsuit  is made with OEKO-TEX certified dyes.

FAQ's

Can you wear swimwear in a sauna?
Yes. In most Australian public and communal saunas, swimwear is required, along with a towel to sit on.

 

What temperature is a sauna?
Traditional Finnish saunas generally run 70–100°C. Infrared saunas run cooler, typically 45–60°C.

 

Is polyester or nylon better for sauna swimwear?
Nylon. It holds shape and colour under heat and moisture cycling, dries faster and resists odour better than polyester.

 

Are swimwear dyes safe at high temperatures?
Heat increases skin permeability, so dye quality matters more in a sauna than at the beach. Look for OEKO-TEX® STANDARD 100 certification.

 

Can I wear the same swimwear for sauna and cold plunge?
Yes, and ideally you should. One piece that handles both extremes means you're not thinking about your swimwear mid-ritual.

 

How often should I replace sauna swimwear?
With regular use and proper care, 12–18 months before significant stretch loss. Rotating two suits extends this considerably.

 

What should I bring to a sauna session?
Swimwear, a towel to sit on, a second towel to dry off, water or coconut water, heat protector for your hair, a sauna hat (optional), post sauna body + face moisturiser, SPF50+ and a change of clothes. Some venues provide towels — check when you book. 

 

Join One for the complete Sauna guide. Everything you need to know before you sauna. 

 Explore our wellness swimwear made to support your rituals.

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