A towel is the least technical sauna accessory. It’s also the one both the manual and Finnish custom agree on.
This article covers why you use one, what size to buy, and where to put it. For the rest of the accessories, start with the sauna accessories buying guide.
Short answer: sit on a towel every session. Buy one long enough to lie on, and never hang it over the heater.
Why you sit on a towel
Two sources say the same thing for slightly different reasons.
Harvia’s KIP heater manual: “For sanitation, each bather should sit or lie on a towel (this will prolong bench life).”
thisisFINLAND, a guide to Finnish life: place a small towel on the bench to sit on, “both for hygienic reasons and because the bench may feel rather hot.”
So a towel keeps sweat off the wood, keeps the bench cleaner for the next person, and keeps the heat off your skin.
What size to buy
It depends on how you use the bench.
| Use | Size to look for |
|---|---|
| Sitting only | A small towel, per the Finnish guide |
| Lying down or wrapping up | About 90 x 170cm (35 x 67 in.) |
The Harvia Cotton Sauna Towel is the second kind: 90 x 170cm, 100% cotton terry, 600 GSM, $56.80 at The Sauna Place.
What 600 GSM tells you
GSM is grams per square meter. It’s the weight of the fabric, and it’s a number you can compare between towels.
Here’s what the spec sheet won’t tell you: the Harvia listing doesn’t state a drying time. A heavier towel holds more water, so plan on one towel per person per session and a place to dry them.
You get full-length coverage and a stated fabric weight with the Harvia. You give up $56.80, more than a plain bath towel costs. A towel you already own does the sitting job fine.
Where not to put it
Harvia’s manual is direct about this. Don’t place any combustible material over the sauna heater, and it lists towels first.
Hang your towel on a hook away from the heater, or outside the door. The Almost Heaven robe hook ($41) mounts inside or outside the cabin.
Etiquette in company
thisisFINLAND says basic sauna etiquette is simple. Shower before you go in, and sit on a towel. Past that, it says, there are few rules.
My rule of thumb for guests: put a clean towel out for each person, so nobody has to ask.
Keeping the bench clean
A towel doesn’t remove the need to clean. Harvia’s manual says to scrub the benches with a soft brush and soap and water when needed. If the wood gets stained from perspiration, it can be lightly sanded with fine sandpaper.
For cabins and bench layouts, see the home sauna buying guide.
Bottom line: one towel per person, under you every session, and nowhere near the heater.
Sources
- Harvia, KIP electric sauna heater owner’s/operator’s manual (North America), September 17, 2015: almostheaven.net
- thisisFINLAND, “Bare facts of the sauna in Finland,” accessed October 8, 2026: finland.fi
- Harvia Cotton Sauna Towel listing at The Sauna Place and Almost Heaven robe hook listing at Select Saunas, checked September and October 2026