Getting Ahead of Cold and Flu Season, What Heat Therapy Can (and Can't) Do
Last week we mentioned that sauna can help with the aches and stiffness that come with shifting weather, right alongside massage. Today we're going deeper. What heat therapy actually does in your body, what it's genuinely good for, where its limits are, and how to fold it into your own self care without overselling it as a miracle fix.
Why it Eases Sore Muscles and Joints
The mechanism here is largely about circulation. Heat causes your blood vessels to dilate, increasing blood flow to muscles and joints. That extra circulation delivers more oxygen and nutrients while helping clear out metabolic waste products that build up in sore, overworked tissue. It's the same reason a warm compress feels better on a stiff muscle than a cold one, just at a whole-body scale.
Heat also seems to reduce pain sensitivity directly, which brings us to the brain chemistry side of things.
What's Happening in your Brain
This part is genuinely fascinating. Heat exposure triggers a cascade of neurochemical activity:
Dopamine and beta-endorphins. Research has found that sauna sessions can meaningfully raise both dopamine and beta-endorphin levels, and these effects can persist well after you've cooled down. Beta-endorphins in particular play a major role in natural pain relief, binding to the same receptors opioid medications target, minus the downsides.
Dynorphins first, then endorphins. Interestingly, heat stress actually triggers dynorphins first, compounds that create that initial "I need to get out of here" discomfort. That discomfort appears to sensitize your opioid receptors, so that when you cool down afterward, the beta-endorphin rush that follows lands even more powerfully. The uncomfortable part is doing real work.
BDNF. Heat exposure has also been linked to increased brain-derived neurotrophic factor, a protein that supports neuroplasticity and mood regulation.
This combination is part of why people consistently describe a sauna session as leaving them calm, clear-headed, and genuinely happier, not just physically relaxed.
How Much Heat, For How Long?
Infrared saunas heat you, not the room. Instead of warming the surrounding air to intense levels, infrared lamps use light energy that penetrates the skin directly and heats you from within, which lets your body reach a similar core temperature elevation at a noticeably lower, more tolerable air temperature.
Because of that difference, the effective dose for infrared looks different too:
Temperature: most research-backed infrared protocols land in the 120 to 150°F range, well below the 170 to 200°F of a traditional sauna. A commonly cited therapeutic sweet spot is around 135 to 145°F.
Duration: since the ambient air is cooler, infrared sessions generally need to run longer to get the same physiological payoff. Sessions shorter than 15 to 20 minutes tend to fall short of triggering the deeper responses, since your core temperature simply hasn't had enough time to climb. Most research-backed protocols suggest 25 to 40 minutes as the therapeutic range, with studies on cardiovascular benefits specifically using around 30-minute sessions at roughly 140°F to see measurable improvements in blood pressure and blood vessel function.
Sweet spot for beginners: if you're new to infrared, start closer to 110 to 120°F for 10 to 15 minutes, and build up gradually over 2 to 4 weeks as your body adapts to handling heat stress. Jumping straight to a 40-minute session at 150°F on day one isn't necessary and isn't more effective, it just risks you feeling wiped out afterward instead of recharged.
Frequency: as with traditional sauna, consistency seems to matter more than any single session. Several sessions a week is where the more durable benefits, like improved circulation and reduced inflammatory markers, tend to show up, rather than from occasional long sessions.
One session versus regular use: a single infrared session will still relax tight muscles, ease joint stiffness, and give you that dopamine and endorphin lift in the moment. But research on inflammation and cardiovascular markers consistently shows the more meaningful, lasting benefits building over weeks of regular use, not a single visit.
Sauna Versus a Hot Epsom Salt Bath
You may wonder, what can a sauna session do that a hot bath can’t? Both work through the same basic principle: raising your core body temperature to trigger dilation, circulation, and that broader relaxation response. A hot bath is a completely reasonable and accessible substitute if a sauna isn't available.
The differences are mostly about degree and duration. A sauna can sustain a higher, more consistent ambient heat for longer without your extremities cooling the water down, which tends to produce a more pronounced core temperature rise. Epsom salt specifically adds magnesium, which some people find supports muscle relaxation. A bath is a lovely, valid tool, especially on a night when a sauna isn't accessible.
What About Immunity?
Large Finnish cohort studies have found that people who use the sauna more frequently have a lower long-term risk of respiratory diseases like pneumonia, and some data suggests short, intense heat exposure to the airways can reduce viral shedding during a cold. That's a genuinely interesting association.
This doesn't mean that a sauna session will stop you from catching something you've already been exposed to, or replace basic habits like sleep, hydration, and hand washing during cold and flu season. Think of sauna sessions as a supportive piece of a broader immune-supportive routine instead of a substitute for the fundamentals.
Dos and Don’ts
Do:
Hydrate well before and after, since sauna sessions cause significant fluid loss through sweat
Start conservative if you're new to it, both on temperature and time, and build up gradually
Pair it with movement or massage for a combined circulation and relaxation effect
Give yourself time to cool down and rest afterward rather than rushing back into activity
Don't:
Use the sauna while under the influence of alcohol, which impairs your body's ability to regulate temperature
Push through dizziness, nausea, or feeling unwell. Step out immediately if that happens
Treat it as a substitute for medical care if you're actually sick or managing a chronic health condition
Skip checking with your doctor first if you're pregnant or have a cardiovascular condition, since heat stress does raise heart rate and isn't appropriate for everyone without guidance
My Own Sauna Journey
I began using the sauna consistently this past early summer as a way to help build heat tolerance as I continue to heal from Long Covid. As I have talked about in previous Wellness Wednesdays, I found the infrared option was actually way better for meeting me where I was in my healing process. I didn’t have to white-knuckle it through a 20 minute 170-degree session. I was able to set it to a level that challenged me without wiping me out for the rest of the day.
For a long time, sauna was a challenge I was building tolerance toward. Now, as the weather turns colder, it's become something different for me: a comfort. I use it to support circulation in a body that doesn’t work quite as well as it could, to help keep my mood steady and recharged, and to support recovery as I slowly rebuild my exercise tolerance.
That adjustability, and the benefits I experienced throughout the seasons, is exactly why I think saunas have a place for such a wide range of people. From the athlete chasing better recovery times to someone managing chronic pain or fatigue who just wants a little more energy and a little less discomfort in daily life, there's room in that sauna for all of it.
Fitting It Into Your Self Care
Heat therapy earns its place as a real, well-supported tool for supporting circulation, easing muscle and joint tension, lifting your mood, and giving your body a manageable challenge that leaves it a little more resilient, especially heading into the colder months when your body could use the extra support.
That's exactly why we've introduced sauna packages here at Jazz Hands. Since the research is so clearly pointing toward consistency mattering more than any single session, we wanted to make it easy to build regular sauna use into your routine rather than treating it as an occasional add-on. Pair it with your massage sessions and you've got a genuinely strong combination for the season ahead.
If you've been curious, this is a great time to give consistent use a real try. Notice what a few weeks of regular sessions actually does for you: how your body feels day to day, whether your sleep shifts, whether your mood feels steadier, and how your recovery holds up after a workout or a long week. Ask us at your next appointment about current package options, and let's find a rhythm that fits your life.
References
Kunutsor, S.K., Laukkanen, T., Laukkanen, J.A. Sauna bathing reduces the risk of respiratory diseases: a long-term prospective cohort study. European Journal of Epidemiology, 2017.
Laukkanen, T., Khan, H., Zaccardi, F., Laukkanen, J.A. Association Between Sauna Bathing and Fatal Cardiovascular and All-Cause Mortality Events. JAMA Internal Medicine, 2015.
FoundMyFitness (Dr. Rhonda Patrick). The Ultimate Guide to Saunas & Heat Exposure.
News-Medical. The Science of Sauna & Heat Exposure, 2025.
NeuWrite San Diego. Science Meets Serenity: Benefits of Sauna Use on the Brain, 2023.
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