Dress code. Yes, you do have to be naked, and no, you can't keep your underwear on like you did in the showers at school. You'll probably be asked to leave if you insist on wearing any clothing. It's a good idea to have two towels. One to place on the wooden bench under your feet (this prevents the spread of nasty things like verrucas) and one to sit on. Remember to remove any metal jewellery before you go in the sauna, as it could get very hot and burn your skin.
It's also a good idea to bring a bathrobe, as larger public saunas normally have a cafe or snack bar serving light meals and drinks, and a robe comes in handy. Flip flops are also a good idea for wearing in between sauna sessions, but leave them outside the door when you go in the sauna.
Cleanliness. Do have a shower first, before entering the pool or sauna. And do hose down the bench where you've been sitting in the steam room before you leave. No one wants to sit in a pool of your sweat.
Close the door! When you go into the sauna room itself, you must open and close the door quickly. If you forget, you may hear a cry of ‘Tür zu!' (close the door). It's important that the heat is retained within the sauna.
Grooming. Going to the spa and shaving your legs in the shower or steam room is a no no. Same goes for plucking chin hairs, clipping nails or any other grooming routines that should only be done in the privacy of your own bathroom at home.
Talking. Is allowed but keep it quiet and to a minimum. People do greet each other as they enter the sauna, and sometimes there is a bit of banter but don't let it get out of hand.
No ogling. Yes, everybody is naked and you will see bodies of all shapes and sizes but this isn't an excuse to stare. Saunas are about relaxing and Austrians consider them a holistic treatment which benefit the body and mind - especially after a long day hiking or skiing. If you're looking for a hookup, stick to Tinder.
Laughing. Try not to giggle and snigger when the usually male sauna attendant comes in for the ‘Aufguss', and whirls a towel around his head. This is when the water is mixed with essential oils and poured onto the glowing coals of the sauna - making the heat shoot up drastically for a few minutes. Try not to go in or out of the sauna during these moments and keep the door closed. Do clap when the sauna attendant has finished.
Fainting. If you feel very unwell and think you might faint because of the heat, please leave the sauna as soon as you can. Vomiting or passing out on the naked person next to you is a no no.
Avoid the top bench if you're a newbie. This is because heat rises, and it's a long way down if you start to feel unwell. It's recommended that those who are new to the sauna only stay in for around 8 to 10 minutes and sit on the middle or lower bench, at a temperature of 60 to 70C.
Sex. Absolutely not. Don't see an empty sauna or steam room as an excuse to get jiggy with your partner, like these couples did. You will be banned from the spa if you are caught in the act.
Don't over do it. People generally take up to three sauna sessions in one visit, lasting anything from 5 to 20 minutes each. The ‘rest periods' in between - either outside in the fresh air or in a cooler relaxation room - should last at least as long as the previous sauna session; 20 to 30 minutes is recommended. A complete sauna visit takes two to three hours. Don't be surprised if you feel tired after the sauna. Remember to drink plenty of water after your sauna session (but not during) and avoid alcohol.
And don't forget that some Austrian spas offer free entry if it's your birthday!