How we test cold plunges and saunas

Hi, I'm Nora Vance. I'm a cold-water swimmer and recovery-gear tester, and I've installed and lived with cold plunges, infrared and barrel saunas, and sauna blankets in my own house. Cold Cedar Co exists because most of what I read before buying my first plunge was either marketing copy or a one-paragraph "review" written by someone who clearly never filled the thing with water. So I do the boring part for you: I run the gear for weeks, I track the numbers, and I tell you where you can spend less.

Here is the short version of my method, what I measure, and how I keep this honest. I'm a tester and an enthusiast, not a doctor, and I'll flag that again wherever it matters.

What testing actually looks like

I don't do a quick unboxing and call it a day. Every product I rank in our best cold plunge tubs and best infrared saunas guides has spent at least a few weeks in my normal routine, used the way you'd use it: a few cold sessions a week, sauna a few evenings a week, in real weather, on a real outdoor outlet.

That means I assemble the thing myself (no white-glove install), live with it through warm days and cold nights, and pay attention to the small stuff that only shows up over time. Does the chiller keep up when it's 90 degrees out? Does the gasket leak after a month? Does the sauna door still seal once the wood has moved a little? A spec sheet can't answer any of that, but a few weeks of using it can.

For plumbed plunges with a chiller and filtration (think Plunge or Renu, roughly $5,000 to $12,000), I run the filter cycle the way a normal owner would and note how often the water actually needs changing. For an upright like the Ice Barrel (around $1,200), I test it both with ice and paired with a separate chiller. And I always build the cheap version too, because honestly, a stock tank plus a budget chiller gets a lot of people most of the benefit. More on that below.

The metrics I actually track

I try to put a number on everything I can, so two products are compared on the same yardstick instead of vibes. Here's what I record for cold plunges and saunas.

For infrared specifically, I note the low-EMF claim because it's a genuine selling point on these cabins, and I pay attention to whether the brand is transparent about it. I won't invent an EMF figure I can't verify, and I won't repeat a number a brand can't back up.

The cheap path gets its own test

This is the part premium brands don't love, and it's exactly why I'm independent. Before I tell you to spend five figures, I test what the same money saved would buy you instead.

A stock tank with a cheap inline chiller (roughly $500 to $1,500 all in) genuinely works, and I run that build alongside the expensive plunges so you can see the gap for yourself. Honestly, plenty of people get most of the cold-exposure benefit from a cold shower and a few bags of ice in a tub. That costs almost nothing. I cover the trade-offs in our DIY cold plunge guide and break down the numbers in our cold plunge cost piece, and I walk through chiller options in our cold plunge chiller guide.

The catch with any plunge is the same: you need a chiller, you need filtration if you don't want to drain it constantly, and you need a proper GFCI outlet. A premium tub like Plunge bundles all of that into one tidy package, which is worth real money to some people and not worth it to others. My job is to tell you which camp you're probably in, not to push you toward the priciest box.

How I handle the health claims

Cold plunging and sauna use are wellness topics, so I'm careful here. The research is still emerging, a lot of it comes from small studies, and the honest answer to "will this fix my recovery / sleep / mood" is usually "it may help some people, and we don't fully know yet."

So I hedge on purpose. When I write that cold exposure may support recovery or that heat may help you relax, that's the most the evidence supports, and I say so. You'll see the same careful framing in our cold plunge benefits and infrared sauna benefits explainers. I won't claim a cure, a guaranteed outcome, or a specific medical result, because I can't, and neither can anyone selling you a tub.

To be very clear: I'm a tester and an enthusiast, not a doctor. If you have a heart condition, high blood pressure, or you're pregnant, talk to your doctor before cold plunging or using a sauna. Cold and heat both put real stress on your body, and that conversation is worth having before you start.

How I stay independent

Cold Cedar Co makes money through affiliate links. When you buy through a link like our Sun Home review or our HigherDOSE sauna blanket review, we may earn a commission at no extra cost to you. That is the whole business model, and I'd rather be upfront about it than pretend otherwise. The full details are in our affiliate disclosure.

Here's the line I don't cross: affiliate links never change our rankings. A brand cannot pay to move up, and a higher commission doesn't earn a higher spot. I've put cheaper products and DIY builds above expensive partners plenty of times, because that's what the testing showed. If Sun Home or HigherDOSE earns the top of a guide, it's because it held its temperature, heated up fast, ran quietly, and survived weeks of use, not because of the link.

I buy a lot of this gear myself, and when a brand sends a unit to test, that doesn't buy a good review either. You can read more about who I am on the about page, or check my reasoning on the bigger questions in sauna vs cold plunge and cold plunge vs ice bath.