Sauna, Salt Therapy, and Winter Illness
Does Sauna Actually Help Your Immune System?
Short answer: there's real evidence that regular sauna use is associated with fewer serious respiratory infections.
It's October in the Ohio Valley, which means you have roughly eight weeks before everyone you know is sick. Here's what heat and salt can honestly do about that.
What the research found
The strongest finding comes from a Finnish cohort study published in the European Journal of Clinical Investigation. Researchers followed 2,275 middle-aged men for a median of 26.6 years, during which 529 developed pneumonia.
Men who used a sauna two to seven times a week had a 19% lower risk of pneumonia than men who went once a week or less. Combined with good cardiorespiratory fitness, the risk reduction reached 38%.
That's a long, large, carefully conducted study finding a meaningful association. It's also observational research on traditional Finnish sauna, which matters for how much weight to give it. The full caveats are at the bottom of this post, and they're worth two minutes of your time.
Why heat might do anything at all
A sauna session raises your core temperature, which is a mild, controlled version of what your body does on purpose when it runs a fever.
That matters because fever is not a malfunction. It's a deliberate immune strategy. Raising body temperature makes conditions less hospitable for some pathogens and appears to increase circulation of white blood cells. Researchers studying sauna have measured short-term increases in white blood cell counts after sessions.
Heat also improves circulation generally, which means immune cells move through tissue more efficiently.
Whether that adds up to catching fewer colds is the question the research hasn't settled. The mechanism is plausible. The real-world effect size is still fuzzy.
Where salt therapy fits
HALO salt therapy is a different tool for a different part of the problem.
Breathing in pharmaceutical-grade dry salt is about your airways rather than your whole system. Salt is hygroscopic, meaning it draws water toward it, and the thinking is that inhaled salt particles help thin mucus and make it easier to clear. It's the same basic principle behind the saline rinse your doctor recommends.
The research base here is thinner than for sauna, which we'd rather say than dress up. What we hear consistently from clients is that it helps them breathe easier during congested stretches, and that they come more often in allergy season and in the depths of winter.
If you're already dealing with winter congestion, it's the service most of our clients reach for.
What about when you're already sick?
This comes up constantly, and the answer is more specific than yes or no.
If you have a fever, skip it. Your body is already running hot and managing fluid loss. Adding heat and more dehydration works against you. Stay home.
If it's a head cold with no fever, a sauna session may genuinely feel good. Warm air can loosen congestion, and plenty of people find it eases the stuffy misery. It won't shorten the cold.
If you're in the contagious stage of anything, stay out of shared spaces. That includes ours. We'd much rather reschedule you than have you share it with the room.
Hydrate more than you think you need to, before and after, any time you're using heat while run down.
What a realistic winter routine looks like
The research that found an effect looked at people using a sauna two to seven times a week, over years. That's the shape of it. Frequency over time, not a heroic session in January when you already feel something coming on.
Two to four sauna sessions a week through the winter is a reasonable target for most people.
Add salt therapy once or twice a week if congestion is your particular winter problem, and more often during a bad stretch.
The harder part isn't the protocol, it's December. Most winter routines don't fail in February, they fail the first genuinely miserable week when leaving the house feels like too much. Decide now what you're going to keep doing when it's dark at five and 34 degrees.
One more thing winter takes from you
The part nobody puts in the immune-support articles is that winter is isolating, and isolation is its own health problem.
You see people less. You cancel more. The months when your body is under the most strain are the same months you're most likely to be doing everything alone.
That's a real reason we built the studio the way we did. Come with a friend, make it a standing thing, and let it be the reason you leave the house on a Tuesday in January. The sauna is good for you. So is the person next to you in it.
Come get warm
Norton Commons in Louisville, or Main Street in Clarksville. The fireplace is on, the sauna is hot, and we'll help you figure out what makes sense for your winter.
Bring the friend who also hates the winter.
xo, Cass & Jess
Click HERE to book.
FAQs
Does sauna boost your immune system? Research has found that frequent sauna use is associated with a lower risk of respiratory infection. A Finnish study of 2,275 men found a 19% lower pneumonia risk among those using a sauna two to seven times a week. It's observational research on traditional sauna, so it shows association rather than proof, and it isn't a guarantee against catching a cold.
Can you use a sauna when you're sick? Not with a fever. Your body is already managing heat and fluid loss, and a sauna adds to both. With a mild head cold and no fever, a session may help you feel less congested, but it won't shorten the illness, and you should stay out of shared spaces while you're contagious.
Does salt therapy help with congestion? Salt draws water toward it, and the idea is that inhaling fine dry salt particles helps thin and clear mucus. The research base is thinner than for sauna. Our clients consistently report easier breathing during congested stretches, which is experience rather than evidence.
How often should you use a sauna in the winter? Two to four sessions a week, twenty to forty minutes each. The research showing an association with fewer respiratory infections looked at people going two to seven times weekly over years.
Should I come in if I think I'm getting sick? If you have a fever or you're contagious, stay home and reschedule. We would much rather see you next week than have you share it with the room.
The fine print (worth reading)
We'd rather you have the whole picture than a tidy version of it.
The research is observational. The pneumonia study shows association, not proof of cause. People who use a sauna several times a week may simply be healthier in ways the study couldn't fully account for.
It studied traditional Finnish sauna, not infrared. The mechanisms overlap but they aren't identical, and it would be overstating things to pretend the findings transfer cleanly to infrared.
Check with your doctor first if you're immunocompromised, pregnant, or managing a heart or blood pressure condition before starting a regular sauna routine.
Sources for your reference
Kunutsor SK, Jae SY, Laukkanen JA. "High fitness levels, frequent sauna bathing and risk of pneumonia in a cohort study." European Journal of Clinical Investigation, 2021. 2,275 men, 26.6 year median follow-up, 529 pneumonia cases. HR 0.81 for 2 to 7 sauna sessions weekly; HR 0.62 combined with high fitness.
Ernst E, et al. "Regular sauna bathing and the incidence of common colds." 1990. Small and dated. Referenced, not leaned on.
