The sauna is one of the oldest skincare practices in existence, and in Estonia and Finland, it’s a cultural institution rather than an occasional luxury. Done correctly, regular sauna use genuinely benefits skin: it improves circulation, promotes deep sweating that clears pores, temporarily reduces cortisol, and provides the kind of full-body heat therapy that supports overall skin health. Done without any care for what comes before and after, it can leave skin dehydrated, sensitive, and disrupted.
What happens to skin in the sauna
Heat increases blood flow to the skin as the body tries to dissipate core heat. Capillaries dilate, circulation increases dramatically, and skin surface temperature rises. Sweating begins, and for a typical sauna session, a person can lose between half a litre and a full litre of water through sweat.
The steam and heat open pores, not in the sense of physically enlarging the pores (a common misconception), but in the sense of softening the sebum and dead skin cells that can block follicles, making them easier to clear. The cleansing effect of sweating is genuine: sweat carries sebum, cellular debris, and trapped particles out through follicle openings.
Skin also loses a significant amount of moisture during sauna exposure. The high temperature and relatively low humidity of a traditional Finnish or smoke sauna means transepidermal water loss increases substantially. The skin surface, while sweating, is also losing moisture to the dry air, and the net effect on skin hydration depends on what you do before and after.
Before the sauna
Clean skin responds better to sauna than skin with heavy products on it. If you’re going to sauna in the evening, cleansing before you enter makes sense: sweat mixed with makeup, heavy sunscreen, and styling products is not doing your pores any favours.
Don’t apply thick creams or oils immediately before entering. They’ll melt, feel unpleasant, and can interfere with the natural sweating process. If you want to use a nourishing oil mask in the sauna (a popular technique), use a very light application of a penetrating oil like jojoba or rosehip, which benefits from the heat and increased circulation to absorb more deeply. This is different from applying a heavy night cream.
Drink water before a long sauna session. Pre-hydrating means you have more fluid reserve to lose through sweating without reaching significant dehydration. This is relevant both for how you feel during the sauna and for how quickly your skin recovers its hydration afterwards.
During the sauna: hair and scalp considerations
The heat and steam that benefit skin are more complicated for hair. Repeated high heat exposure, especially in a dry sauna, degrades the cuticle and increases hair porosity over time. Wrapping hair in a towel or wearing a sauna hat (the distinctive hat worn in Finnish and Estonian saunas) protects hair from direct heat while allowing you to enjoy the full sauna experience.
Applying a small amount of oil to hair before entering the sauna is a traditional practice in Nordic countries. The heat helps the oil penetrate more deeply, providing a treatment while the sauna session continues. Any oil works for this purpose; lighter oils like argan or jojoba penetrate well without leaving hair excessively greasy after rinsing.
After the sauna: the critical window
The period immediately after sauna is when skincare actually counts most. Pores are clear, circulation is at its peak, and the skin is warm and more permeable than usual. Applied products penetrate more effectively in this window.
First, cool down. Coming out of a sauna directly into cold water (the traditional finish) or cool air lowers skin temperature and begins the process of returning circulation to normal. This cold-hot contrast is a traditional part of sauna culture in Estonia and Scandinavia and is thought to improve circulation and reduce inflammation. It also feels genuinely invigorating.
Drink water after the sauna. Replacing the fluid lost through sweating is essential for rehydrating skin from the inside and for how you feel generally.
Then moisturise. The post-sauna skin, with open pores, increased permeability, and warm temperature, is extremely receptive to topical products. This is when a good moisturiser or facial oil provides more benefit than at any other point in the day. Apply to slightly damp skin for maximum moisture retention.
A rich plant oil applied immediately post-sauna provides both the lipid replacement the skin needs after heat exposure and takes advantage of the enhanced absorption that warm, open-pored skin offers. The sauna tradition of applying birch or other plant preparations to the skin after heating is ancient and, from a skin physiology standpoint, genuinely effective timing.
Sauna frequency and skin type
For oily and acne-prone skin, two to three saunas per week can genuinely help by clearing congestion from follicles. The key is moisturising adequately afterwards to avoid the compensatory oiliness that comes from dehydration.
For dry and sensitive skin, less frequent sauna (once a week) with very attentive post-sauna moisturising makes the experience beneficial rather than a source of dehydration. Be particularly careful about skin that’s currently in a barrier-compromised state (active eczema flare, freshly exfoliated skin, or active sensitisation) and avoid sauna during those periods.
For combination skin, the pore-clearing benefit is primarily in the T-zone. Post-sauna moisturising should be more generous on dry cheeks than the T-zone, in line with how combination skin is generally managed.
Sauna and specific skin conditions
Rosacea and very reactive skin should approach sauna cautiously. The heat and vasodilation can trigger significant flares in people prone to facial redness and inflammation. If you have rosacea, starting with very brief, lower-temperature sauna sessions and having a cooling spray or cold water available to cool the face during overheating is the cautious approach.
For skin conditions that have been cleared for exercise-level heat exposure by a doctor, regular sauna is generally safe. For active inflammatory conditions, check with your dermatologist before adding regular sauna to your routine.