Why I Started Sweating on Purpose
(and freezing on purpose, too)
Story by Dr. Edwin Spencer
Appeared in Cityview Magazine, Vol. 42, Issue 4 (July/August 2026)
My infrared sauna sits in the corner of my home gym, and for years I treated it like a piece of furniture. I would glance at it on the way past, vaguely guilty, the way you might look at an exercise bike you keep meaning to use. Then about three years ago — for reasons I cannot fully reconstruct now; a stiff back, a bad few days of sleep, a podcast, I do not remember — I started getting in. Three or four times a week. Thirty minutes. That’s all.
Then a friend told me he built a cold plunge in the garage, a far more impressive name than “fifty-gallon stock tank from Tractor Supply with an aquarium chiller,” which is what it actually is. I usually stick to cold showers myself, but I have subjected myself to cold plunges before. With these experiences under my belt now, I want to tell you what I think is true and what I think is hype, because both heat and cold have become wellness commodities and the honest middle ground is hard to find.
Let Us Start With the Heat
The evidence here is older and stronger. The Finnish, who treat the sauna the way the rest of the world treats coffee, gave us the foundational dataset. A long-running cohort study followed thousands of middle-aged Finnish men for two decades and found something striking: men who used the sauna four to seven times a week had roughly half the risk of fatal cardiovascular events compared to men who used it once a week. Half. The same dataset showed reductions in all-cause mortality, dementia, and Alzheimer’s disease. Those numbers caught attention, and a wave of follow-up research has largely held up the basic finding — sauna use, done regularly, looks a lot like exercise from the cardiovascular system’s point of view.
What is actually happening in there? Heart rate climbs into the same range you would hit on a brisk walk or a light jog. Blood vessels dilate. The body releases heat shock proteins, which help cells repair and refold damaged proteins. Blood pressure drops in the hours afterward. Inflammatory markers fall. The mechanisms read like a list of everything cardiology spent fifty years figuring out exercise was doing — and the sauna seems to do a remarkable amount of it without you ever leaving the bench. However, let me be clear that there is no substitute for actual training.
Now to the question you actually want me to answer: does my infrared sauna count? The honest answer is — probably, mostly, but the evidence is thinner. Most of the research used traditional Finnish dry saunas at 175 to 212 degrees Fahrenheit. Infrared saunas top out closer to 140 degrees and heat the body more directly through radiation rather than the surrounding air. The cardiovascular response is real but somewhat smaller. The research catalog is much smaller, too. There is some evidence infrared may help more with chronic pain and joint stiffness specifically. What there is not yet is a Finnish-style cohort study showing infrared cuts cardiovascular mortality in half. So, when I describe my sauna habit, I describe it accurately: I am reasonably confident I am doing something good; I am not confident I am doing exactly what those Finnish men did.
I like to use the sauna after training, and it is a great place to read. Add some essential oils and you have a sweaty aromatherapy session that is hard to beat.
A Quick Untangling: Two Things Called “Infrared”
There is confusion baked into the wellness conversation around “infrared” that I had to work through myself, and it is worth a few paragraphs here because most readers — and many writers — conflate them. The infrared sauna I sit in and the red-light panel your friend on Instagram swears by are both called infrared, but they are different machines doing different things. My sauna delivers far-infrared wavelengths that are absorbed in the first millimeter of skin — the benefit is the heat. A red-light panel delivers near-infrared wavelengths in the 600-to-1,100 nanometer range that penetrate centimeters into tissue and activate enzymes inside the mitochondria — a photochemical effect, not a thermal one. Some all-in-one saunas include both. Mine does not. The mitochondrial and glucose-control claims you may have heard about belong to that second device, not the first.
Together they are something like a small, repeated argument with comfort.”
We have one of those second devices — a near-infrared panel — and use it separately on whatever is complaining that week, usually for ten to twenty minutes. The mechanism, briefly: photons in the 600-to-900 nanometer range are absorbed by an enzyme called cytochrome c oxidase in the mitochondrial inner membrane, causing the electron transport chain to run a bit more efficiently and ATP production to climb. The clinical literature is much smaller than the sauna literature, but it is interesting. A 2024 University College London study found that a single 15-minute exposure at 670 nanometers reduced post-meal blood glucose by roughly 28 percent in healthy adults. Smaller trials suggest improvements in insulin sensitivity and skeletal muscle glucose uptake. The studies are short, the populations are small, and there is no equivalent of the Finnish cohort, but the mechanism is well-characterized, and the early human signals are real enough to take seriously.
We use the near-infrared panel to treat some chronic low back pain and surprisingly it helps. I was a skeptic at first, and it might be placebo, but I don’t really care – the back pain is better.
And Then the Cold
Here the science is younger, noisier, and more contested. The headline benefits are real but easier to oversell. Cold water immersion at 50 to 60 degrees Fahrenheit for three to ten minutes does measurable things: norepinephrine spikes by two to five times baseline, dopamine climbs and stays climbed for hours, mood lifts, and focus sharpens. A 2025 systematic review published in PLOS One found that people who use cold water immersion regularly report meaningful improvements in stress, sickness absences, and quality of life.
There is even a nice clean number — Susanna Søeberg, the Scandinavian researcher whose work most of the cold-plunge community cites, has suggested that about eleven minutes of cold exposure per week, broken across a few sessions, is the threshold where measurable metabolic changes begin to show up. That is a manageable target. Eleven minutes a week is a lunch break, not a lifestyle.
What the cold does not do, and what wellness Twitter would rather not tell you, is reduce inflammation in a way that makes you stronger from your workouts. The opposite, actually. There is now reasonably solid evidence that cold immersion done immediately after resistance training blunts the muscle-building response. So, if you lift, plunge in the morning, not after the gym. The cold also does not melt fat in any clinically meaningful way despite many enthusiastic Instagram captions to the contrary. And the recovery claims for endurance athletes — which is where the whole modern cold plunge movement actually started — have been getting watered down by recent meta-analyses showing it works modestly, not magically.
For some reason I wanted to see how long I could plunge at 50 degrees. It is miserable at first but then you can feel your heart rate drop and you acclimate. After 20 minutes I started to shiver and after 25 minutes I had enough. It took a good while to thaw out as my wife peppered me with the obvious question: “What the hell were you thinking?” Now I stick to much shorter sessions.
What Three Years Has Actually Taught Me
The effects are less dramatic than the wellness influencers would suggest and more dependable than I expected. The sauna is meditative; I read in there, and I think more clearly when I get out. I sleep better on nights I sat in it, especially if done a few hours before bedtime. The cold is not meditative — the cold is a small and consensual emergency. There is no thinking your way through it; there is only being in it. What it gives me every time is about four hours of what I can only describe as cleanness — mental quiet, physical alertness, an unreasonably good mood. Whether that is the dopamine doing its thing or just the contrast of being warm again, I genuinely do not know. I do know that I keep coming back.
The sauna is meditative. The cold is a small and consensual emergency.
If You Are Going to Start
Here is what I would actually tell you.
For the sauna: any kind beats no kind. Aim for sessions of 15 to 20 minutes, three or four times a week. Build up gradually. Hydrate the way you would for exercise, because that is what your body thinks you are doing. If you have unstable blood pressure or active cardiovascular disease, talk to your physician first.
For the cold: start in a cold shower, not a plunge. Three minutes at the coldest your tap will go, and turn it off when you start shivering hard. Work toward two or three sessions a week. The 11-minute weekly target is a useful goal, not a daily prescription.
Do not put yourself in cold water alone the first few times if you have any cardiovascular history. The cold-shock gasp reflex is real and the cardiac strain is genuine.
If you lift weights, plunge before the gym or at least six hours after, not immediately after.
If you want to add a near-infrared light panel, treat it as a separate practice with its own dosing — typical protocols are 10 to 20 minutes at a distance of six to twelve inches, three to five times a week, on the body region you care about. The early human evidence for glucose and recovery effects looks promising; the evidence base is far smaller than for sauna or cold.
The Quieter Version
Three years in, I am a believer. Not in the influencer version of either practice, where the sauna fixes your hormones and the cold plunge fixes your soul, but in the older and quieter version: that doing hard things to your body on purpose, regularly, in small enough doses to keep doing them, seems to make you measurably more resilient. My infrared sauna is not a miracle. Cold immersion is not either. Together they are something like a small, repeated argument with comfort. I find I am better, on the whole, for using it.
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