A Thai herbal steam sauna is a small room or cloth tent filled with steam from a pot of boiling herbs such as kaffir-lime peel, lemongrass and turmeric. You sit in it for short rounds of 10 to 15 minutes, cool off outside in between, and drink water afterward. It is hot, simple and not for everyone: Thai hospital guidelines list fever, pregnancy and heart disease among the reasons to stay out.
In Thai the treatment is called op ai nam samunphrai, "herbal steaming". You find it in some temple grounds, village health and community-tourism projects, day spas and the Thai traditional medicine clinics of hospitals. It belongs to Thai traditional medicine, not to the Finnish sauna tradition: the heat is wet, the air smells of citrus and camphor, and the session is shorter. This page explains the herbs, how a visit works and the safety rules. We make no health claims for it.
Thai herbal steam at a glance (October 2026)
- Thai name
- Op ai nam samunphrai (herbal steaming); the cloth tent is a krachom
- Typical herbs
- Kaffir-lime peel, turmeric, lemongrass, tamarind leaves, som poi leaves, camphor (Ramathibodi Hospital)
- One round
- 10-15 minutes, then about 5 minutes outside; two rounds (Ramathibodi)
- Upper limit
- Not more than 30 minutes in total (Siriraj Hospital)
- Do not use with
- Fever over 38.5 °C, pregnancy, menstruation, heart disease, severe asthma, open wounds (full list below)
- Price
- No official or published price list found; ask at the door
What the steam is made of
The method is the same everywhere. Fresh or dried herbs, mostly aromatic ones with essential oils, are boiled in water, and the steam is led into a small room, a wooden cabinet or a cloth tent. The Thai word krachom covers that tent: the Royal Society's dictionary defines it as cloth made into a tent that a person sits in to sweat.
The alternative-medicine unit at Ramathibodi Hospital in Bangkok lists the usual ingredients as kaffir-lime peel, turmeric, lemongrass, tamarind leaves, som poi leaves (from a climbing acacia) and camphor, "and other Thai herbs". Several of these are the same plants you meet in a green curry or a fresh-market herb stall, which is why a steam room can smell like a kitchen at lunchtime.
Recipes differ from place to place, and many sellers and spas name a herb called plai (a ginger relative). Neither hospital page we read lists it, so treat any specific mix as the house recipe rather than a standard.
Temples, villages, spas and hospitals: who runs one
Herbal steam rooms are part of the health services that some temples and village projects have long offered, often next to a massage pavilion. They are usually simple: a tiled or wooden room, a gas burner under a big pot, a bench outside and a tap or bucket shower. We could not find an official, dated list of temples that run one, so we do not name any. The easiest way to find one is to ask at a local massage shop, at your guesthouse or at the temple office.
The one dated example we found from the Tourism Authority of Thailand (TAT) is a village, not a temple. In a December 2019 feature, TAT described a herbal steam bath at the Chong Chang Tune Live Ecomuseum in Bo Rai district, about 50 minutes by car from Trat town, where the local Chong community seats guests inside a chicken-coop frame with only their head sticking out, using herbs gathered around the village. We have not confirmed that it still runs in 2026; it fits a trip to the islands off Trat or a community-based homestay, but check locally first.
At the other end of the scale, the Thai traditional medicine clinics of large public hospitals, such as Siriraj in Bangkok, offer herbal steaming as a treatment after a consultation. Hotel and day spas sell it as an add-on, usually at spa prices. Thai massage shops sometimes have a steam cabinet in the back; our guide to Thai massage covers the separate herbal compress treatment, which is pressed onto the body during a massage rather than breathed in a steam room.
How a session works
Ramathibodi's guidance gives the basic rhythm, and the rest is common practice in simple Thai steam rooms:
- Arrive rested, not full. Siriraj's guidelines say not within 30 minutes of a full meal, and not when you are exhausted, short of sleep or fasting.
- Change. Expect to wear a sarong, a wrap or swimwear rather than go naked; ask what the place provides and where to leave your things.
- First round: 10 to 15 minutes. Sit, breathe normally and leave at once if you feel chest tightness or cannot breathe easily.
- Rest outside for about 5 minutes. Sit down in the shade, rinse off if there is a shower, and let your heart rate settle.
- Second round, then stop. Siriraj sets 30 minutes in total as the upper limit, because longer sessions drain water and salts through sweat and can lead to fainting.
- Drink water or an oral rehydration drink afterward, as Siriraj advises, before you walk out into the sun.
Siriraj says two or three sessions a week is the usual frequency, depending on the person. A tourist doing it once on a slow afternoon is well within that.
Steam, then shade, then water. Go after the hottest part of the day if the steam room is outdoors, and do not plan a long walk or a scooter ride straight afterward. You will sweat for a while after you leave the room.
Who should not use a herbal steam room
Siriraj Hospital's Thai traditional medicine unit publishes a list of contraindications based on the Department of Thai Traditional and Alternative Medicine's 2009 clinical guideline. Do not use a herbal steam room if you have:
- a fever above 38.5 °C;
- exhaustion, lack of sleep, or have not eaten, or have just had a full meal (within 30 minutes);
- a serious infectious disease such as tuberculosis;
- epilepsy, severe asthma, severe kidney disease, heart disease, chest pain or breathlessness;
- blood pressure above 140/90 with dizziness, headache, nausea or vomiting;
- open or inflamed wounds, or a skin infection;
- your period, or a pregnancy;
- an allergy to herbs or to heat.
Siriraj also warns that people with blood pressure below 90/60 or above 140/90 risk fainting and need watching. If any of these apply to you, or you take medicine for blood pressure or the heart, ask a doctor first. If you are traveling while pregnant, our page on pregnancy and travel in Thailand covers the wider picture. Skin problems are common in the tropics, and the page on rashes and infected cuts explains why a fresh coral scratch is a reason to skip the steam.
Ignore promises that a steam bath "detoxes" you or lowers blood pressure. Some spa menus and even one hospital information page list benefits like these. Siriraj's own guideline does the opposite for blood pressure: high blood pressure with symptoms is a reason not to go in.
Thailand's heat makes the steam harder on the body
A steam room in a cool country is a contrast; in Thailand it is extra heat on top of a hot day. You arrive already warm, you lose fluid in the room, and you walk back out into tropical heat. Dehydration after a beer the night before, a long temple walk or a day at the beach adds up faster than most visitors expect.
Our page on coping with heat and sun in Thailand explains the warning signs of heat exhaustion and heatstroke. If you feel dizzy, sick or confused after a session, get out, lie down in the shade, drink and call 1669 for an ambulance if you do not recover quickly. Keep alcohol for later in the evening.
Manners in a temple or village steam room
A temple steam room is still on temple grounds. Dress modestly when you walk between the changing area and the steam room, keep your voice down, and follow the same rules as anywhere else in a wat; our page on temple etiquette and dress has the details. If there is a donation box instead of a price, put something in it before you leave.
The rooms are small and shared. Shower before you go in if there is a shower, sit on a towel or the cloth provided, and do not bring your phone into the steam. Smoking is banned on the whole premises of saunas and spas under a 2018 Ministry of Public Health notification, so the bench outside is not a smoking area either, as our page on where you can smoke in Thailand explains.
Frequently asked questions
How long should you stay in a Thai herbal steam room?
Ramathibodi Hospital's guidance is 10 to 15 minutes per round, about 5 minutes resting outside, and two rounds. Siriraj Hospital sets 30 minutes as the upper limit, because longer sessions drain water and salts and can lead to fainting.
Can you use a herbal steam sauna while pregnant?
No. Siriraj Hospital's Thai traditional medicine guidelines list pregnancy and menstruation among the conditions in which herbal steaming should not be used. Ask your doctor if you are unsure about any heat treatment.
What herbs are used in a Thai herbal sauna?
Ramathibodi Hospital lists kaffir-lime peel, turmeric, lemongrass, tamarind leaves, som poi leaves and camphor, plus other Thai herbs. Each temple, village or spa has its own mix, so ask if you have a plant allergy.
How much does a herbal steam sauna cost in Thailand?
We found no official or published price list, and prices vary from a donation at a temple to spa rates in a hotel. Ask before you change, and check whether a massage is included or charged separately.
Is a herbal steam sauna the same as a herbal compress?
No. In a steam sauna you sit in steam from boiled herbs. A herbal compress is a warm cloth bundle of herbs pressed onto the body, usually as part of a massage.
Sources
- Siriraj Hospital, Mahidol University – Herbal steaming: contraindications and cautions (Thai) (checked October 2026)
- Ramathibodi Hospital, Alternative Medicine Unit – Herbal steaming: method and herbs (Thai) (checked October 2026)
- Tourism Authority of Thailand – The local wisdom of health and wellness can be experienced throughout Thailand (11 December 2019) (checked October 2026)
- Office of the Royal Society – Thai dictionary: krachom (checked October 2026)