Reviewed by Emily Carter, MSc, RD
Registered Dietitian & Hydration Research Specialist. Emily holds a Master of Science in Human Nutrition and has spent over a decade translating nutrition research into practical, evidence-based guidance for everyday health and athletic performance.
Quick answer: The essential sauna kit is: a large insulated water bottle (1.5L minimum), two towels (one for the bench, one for drying), clean swimwear or a wrap towel, flip-flops, and a lock for your locker. Everything else is optional. Leave your phone outside — it does not belong in the sauna and most facilities do not permit it inside the room. Use our sauna hydration calculator to personalise your fluid intake.
The Essential List
1. Water Bottle — The Most Important Item
A sauna session without adequate hydration is a diminished and potentially uncomfortable experience. A 15–20 minute session produces 300–500ml of sweat loss. A full multi-round session can exceed 1.5 litres. You need water accessible throughout — between rounds, during cool-down, and after your final round.
The minimum: 1.5L large-capacity water bottle. The optimal: 2.5L for multi-round or event sessions. The Mammoth Mini 1.5L is the right size for a standard 2-round gym session — wide mouth for ice and electrolytes, wide mouth for adding ice before your session.
For the full guidance on choosing the right bottle specifically for sauna use, see our guide on best water bottle for sauna. For the hydration protocol — how much to drink and when — see our guide on sauna dehydration and fluid replacement.
2. Two Towels
Towel 1 — The bench towel: Always sit on a towel in a shared sauna. This is universal etiquette — protect the wooden bench from direct contact with your skin, and protect yourself from whatever was on the bench before you arrived. Size matters: large enough to cover your seating area fully. A standard bath towel works; a dedicated sauna towel (thicker, more absorbent) is even better.
Towel 2 — The drying towel: A separate towel for drying off after the cold shower or cool-down. Using your bench towel (now wet with sweat) to dry yourself is unpleasant and unhygienic. Keep them separate.
3. Swimwear or Wrap Towel
Check the facility's rules before arriving. Most North American gyms and spas require swimwear; some European facilities are textile-free in the sauna room itself. Bring swimwear that is quick-dry — heavy cotton swimwear becomes uncomfortable quickly in the heat. For longer sessions or events, bring a spare set.
4. Flip-Flops
Sauna facilities involve wet floors, changing rooms, showers, and cool-down areas. Flip-flops protect your feet from floor bacteria and prevent slipping on wet tile. Bring a pair you can slip on and off easily — you will remove them inside the actual sauna room but wear them everywhere else.
5. Locker Lock
If using a facility with lockers, bring a combination or key lock. Many gyms and spas have lockers but do not provide locks. Leaving your phone, keys, and wallet in an unlocked locker while you are in the sauna for 45–90 minutes is not a good plan.
The Useful Additions
Electrolyte Sachets
For sessions over 45 minutes or 2+ rounds, plain water alone may not fully restore your fluid balance — electrolytes lost in sweat (particularly sodium) need replacement. An electrolyte sachet mixed into your water after the second round prevents the post-sauna headache that comes from sodium dilution. Small, lightweight, and worth the space in your bag.
A Light Snack
For sessions over 90 minutes — events, bathhouse evenings, or extended contrast therapy sessions — bring a small snack for the back half. Banana, dates, or rice crackers. Blood sugar dips after multiple sauna rounds and a snack between rounds three and four prevents the energy drop that causes many people to leave early.
A Robe or Warm Layer
For facilities with cool lounging areas, a robe or lightweight layer for the cool-down periods is comfortable. The post-sauna cooling phase is pleasant — but standing around in damp swimwear in a cold changing room is not. A robe makes the cool-down experience significantly more comfortable and encourages you to take a full rest before re-entering.
Hair Tie
If you have long hair, tie it up before entering. Long hair in the sauna traps heat around your head (making you overheat faster), absorbs sweat, and becomes uncomfortable. A simple elastic or clip is all you need.
What to Leave Outside
| Item | Why Leave It Out |
|---|---|
| Phone | Etiquette violation; heat damages electronics; most facilities prohibit it |
| Metal jewellery | Metal heats rapidly — rings, necklaces, earrings can cause burns |
| Valuables | Leave in a locked locker — not in the sauna room or changing room unattended |
| Heavy lotions / sunscreen | Block sweating and pore function; inconsiderate in shared air space |
| Perfume / cologne | Intensified dramatically in the heat; unpleasant for others |
| Food | Odours in shared space; creates mess; not appropriate facility use |
| Alcohol | Dangerous combination with heat — amplifies dehydration and cardiovascular stress |
For Event Sauna (NRG Toronto Sauna Rave)
For a multi-hour sauna event like the Mammoth Mug Sauna Rave at NRG Toronto, the gear list expands:
- Mammoth Mug 2.5L — 3–4 hours of heat cycling requires more than a standard bottle
- 2–3 electrolyte sachets — add after rounds 2, 3, and 4
- 2 sets of quick-dry swimwear — one becomes saturated, change at the halfway point
- 3+ towels — bench towel, drying towel, a spare
- Light snack — for the back half of the evening
- Robe — for cool-down periods between rounds
- Beginner Guide to Sauna: Everything You Need for Your First Session
- How to Prepare for a Sauna Session
- Sauna Etiquette: Rules for Shared and Public Saunas
- Best Water Bottle for Sauna: What to Look For
- Sauna Rave Toronto: NRG Event Guide
Frequently Asked Questions
Do I need a special sauna towel or will a regular bath towel work?
A regular bath towel works fine for most sauna sessions. Dedicated sauna towels are typically larger, more absorbent, and dry faster — useful for longer sessions or if you plan to use the sauna frequently. For a one-off or occasional session, bring whatever large bath towels you have. The key is having two: one for the bench, one for drying.
Can I bring my phone into the sauna?
Most facilities explicitly prohibit phones in the sauna room — both for etiquette reasons (recording other users) and practical ones (heat damages electronics). Even where not prohibited, phones break the shared contemplative atmosphere that makes sauna valuable. Leave your phone in a locked locker. If you need a timer, bring a simple waterproof watch.
What should I wear in a public sauna?
Swimwear is standard at North American gyms, spas, and fitness facilities. Some European facilities are textile-free; some have mixed rules across different zones. Always check the facility's policy before arriving. Quick-dry swimwear is more comfortable than cotton, which becomes heavy and saturated. See the full clothing guidance in our beginner sauna guide.
Should I bring electrolytes to the sauna?
For sessions under 30 minutes, plain water is sufficient. For 2+ round sessions, events, or any session over 45 minutes of total heat time, bring an electrolyte sachet to mix into your water after the second round. Replacing sodium lost in sweat prevents the post-session headaches that come from drinking plain water in large quantities after significant sweat loss. A single sachet of low-sugar electrolyte powder is all you need.
What is the best water bottle size to bring to the sauna?
1.5L minimum for a standard gym session; 2.5L for multi-round sessions or events. A Mammoth Mini 1.5L covers a typical 2-round session without refilling. A Mammoth Mug 2.5L covers extended sessions, event use, or any situation where you want to cover pre-session loading and post-session recovery without a single refill trip. For the full bottle selection guide, see our article on the best water bottle for sauna.
Do I need to bring two towels to the sauna?
Two towels is the standard recommendation: one to sit on inside the sauna (hygiene requirement at virtually every facility — you should never sit directly on the wooden bench) and one for drying off after your post-sauna shower. A third towel for the cool-down area is optional but appreciated if you plan multi-round sessions. Many experienced sauna users bring a small hand towel as well — useful for wiping sweat from your face during sessions and wringing cool water over your head between rounds. Budget saunas rarely provide towels; check your facility's policy before arriving.
What kind of sandals or footwear should I wear at the sauna?
Rubber or EVA flip-flops are essential for walking between the sauna, shower, and cool-down areas. Shared sauna facilities are warm, wet environments where fungal infections (athlete's foot, plantar warts) spread easily. Remove sandals before entering the sauna room itself — rubber can get uncomfortably hot on the upper benches, and some facilities prohibit footwear inside. Avoid fabric slippers (they absorb water and become unsanitary) and avoid going barefoot in the changing room and shower areas. A simple pair of $5 rubber slides is one of the most important things to pack.
Should I bring a bag to carry my sauna essentials, and what material is best?
A small waterproof bag or mesh tote is ideal — mesh allows wet items to air-dry during transport home. Avoid canvas or cotton bags that absorb moisture and develop mildew. Pack list for a standard session: water bottle (2.5L for multi-round sessions), 2 towels, rubber sandals, change of underwear, moisturiser for post-shower, and a small plastic bag for wet swimwear on the way home. If you sauna at your gym, a locker eliminates the bag entirely — just bring a towel and water bottle from home and use the gym's shower supplies.
