How do I book?
You can book from our homepage booking section or the Book a Session button in the site header. From there, you can book as a drop-in or set up a membership.
First Timers
You can book from our homepage booking section or the Book a Session button in the site header. From there, you can book as a drop-in or set up a membership.
At its core, Third Space is small bathhouse with saunas and cold plunges, focused on social connection and wellbeing. We started Third Space in Boulder to create a welcoming, low-pressure space where people can connect and build new communities.
Radical inclusion is at the heart of what we do: no gatekeeping, no pretenses, just you showing up as you are on any day. Whether it’s through open sauna sessions, classes, or simply spending time in the space, we hope to offer something for everyone.
We welcome guests 18 and older.
A swimsuit, required for all sessions.
A towel, we recommend bringing one to dry off and, if you’d like, a small one to sit on in the sauna. We can provide a towel if needed.
A water bottle, no glass.
We have spaces to change but still recommend arriving in your swimwear to make things quick and easy when you get here.
We recommend arriving 10 minutes early so you have time to check in, get oriented, and ease into the experience without rushing.
A simple self-guided rhythm to follow:
10-15 minutes of heat – Spend this time in the sauna to relax your body, open your pores, and get your circulation flowing.
2-3 minutes in the cold plunge – Submerge up to your neck if possible. The key is to stay calm and breathe. Try this:
Inhale slowly through your nose
Exhale even more slowly through your mouth
Keep your breath steady and your mind focused on the sensation
5–10 minutes of rest – Let your body come back to baseline. You can sit, rehydrate, or just hang out around the lounge.
Repeat the cycle as you like, 2 to 3 rounds is a great start for most people.
Bring a swimsuit, which is required for all sessions; a towel to dry off and, if you would like, a small one to sit on in the sauna; and a non-glass water bottle. We can provide a towel if needed.
We welcome drop-ins. You will still need to schedule your session ahead of time.
To help keep things comfortable and respectful for everyone:
Sit on a towel in the sauna, avoid bare skin on the benches.
If you pour water on the sauna stones, use just a little at a time, and check in with others first.
Bring water into the sauna if you’d like, but no alcohol. We won’t admit anyone who’s intoxicated, and we ask that you don’t drink before any session.
Feel free to linger. Our lounge and bar area is open to you for drinks, conversation, or just quiet reflection. Integration is part of the process.
Start with the warmer plunge if you are new. The goal is steady breathing and control, not proving anything.
Yes. Start with shorter rounds, take breaks, hydrate, and choose the sauna temperature that fits your body that day.
Plan enough time for heat, cold, rest, hydration, and transitions. The best rhythm is the one you can repeat comfortably.