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Full Spectrum Infrared Sauna

By Home Sauna Guide · Facts about Plunge as read 2026-10-28 · Updated 2026-10-28

The short answer. Infrared is a band of light we feel as heat, and scientists split it into near, mid and far infrared, though the edges of those three bands are not fixed. For saunas, "full spectrum" is a marketing label, and we could not find a standard that defines it, so the useful question is which heaters a sauna has and what the seller states about them.

Near, mid and far infrared, defined

Infrared sits just beyond the red end of visible light. You cannot see it, but you can feel it. NASA puts it plainly: people encounter infrared waves every day, and although the human eye cannot see them, we can detect them as heat.

Scientists divide the infrared region into three zones by wavelength. The Infrared Processing and Analysis Center at Caltech, which works with NASA's infrared missions, gives these ranges in microns (one micron is one millionth of a metre, or 1,000 nanometres):

BandWavelength range (microns)
Near infraredabout 0.7 to 1 up to 5
Mid infrared5 up to about 25 to 40
Far infraredabout 25 to 40 up to about 200 to 350

Those paired numbers are not a typo. The same source states that the boundaries between near, mid and far infrared are not agreed upon and can vary. A different physics text, a different telescope team or a different sauna company will draw the lines in slightly different places.

Any sauna page that prints exact cut-offs for "near," "mid" and "far" has picked one convention among several.

NASA also gives some everyday reference points that help with scale. A television remote control uses infrared at around 940 nanometres. Infrared heat lamps often give off both visible light and infrared at wavelengths between 500 and 3,000 nanometres. That second figure matters later in this guide, because it shows why a glowing lamp makes both light and warmth.

What "full spectrum" does and does not mean

In a sauna listing, "full spectrum" usually suggests that the heaters cover near, mid and far infrared together. That is a reasonable reading of the words. It is not a defined term.

We searched for an official or standards-body definition of "full spectrum" as applied to saunas and did not find one. The pages we found that explain the phrase were written by sauna sellers, and they do not agree with each other on what qualifies. We have not used them as sources for anything on this page. If you see a definition stated as fact, read it as that seller's definition.

Here is what the label does not tell you:

When a listing says "full spectrum," ask what heaters produce it.

How the heat reaches you

Infrared heaters warm you more directly than a traditional sauna does. Cleveland Clinic describes it this way: infrared saunas warm your body more directly instead of mainly heating the air around you. The same article quotes a typical infrared sauna range of 110 to 135 degrees Fahrenheit (43 to 57 degrees Celsius), against 150 to 195 degrees Fahrenheit (66 to 91 degrees Celsius) for a traditional sauna.

We compare the two in infrared vs traditional sauna, including setup, power and running cost.

Cleveland Clinic's page does not distinguish near, mid or far infrared, and it does not discuss "full spectrum." So the temperature figures above describe infrared saunas in general, not any wavelength mix.

Panels and towers: the two heater types

Most infrared saunas you will see use one or both of two heater designs.

Flat panels. These are the wall-mounted or seat-back heating surfaces, and they spread warmth across a large area. The panel type that Plunge names is far infrared.

Lamps or towers. An incandescent lamp has a filament that glows. It gives off visible light and infrared together, which is why NASA lists heat lamps as emitting across a range that includes visible wavelengths. A tower is simply a housing that holds one or more of these lamps in a column. How much of a lamp's output is infrared, and in which band, is a spec for the maker to state.

A sauna that mixes the two gets a broad blend of heater types. Whether that is better for you is a preference question. We have not used any of these saunas and cannot rank how either feels.

Plunge's setup, as read from its pages

We promote Plunge and earn a commission if you buy through our link. Everything below comes from the Plunge product pages, which we read on 2026-10-28, and is attributed to Plunge.

Per Plunge, both of its infrared saunas use far-infrared panels plus full-spectrum incandescent towers. That is the panel-plus-tower combination described above: panels for broad far-infrared warmth, and incandescent towers that Plunge calls full spectrum.

What we can say from the pages:

What we cannot say, because the pages we read do not say it: the wavelength range of the towers, the power of each heater, or how much of the output is near, mid or far infrared. Plunge calls the towers "full-spectrum." It does not, on the pages we read, publish a band-by-band breakdown. If that detail matters to you, ask Plunge before buying and write down the answer.

Note the temperatures. Plunge's stated maximums of 160 and 175 degrees Fahrenheit sit above the 110 to 135 degree range Cleveland Clinic quotes for infrared saunas generally. A maximum is a ceiling the control can reach, not a recommended setting. Start low and build up, as the sauna guidance in the next sections suggests.

For the spec-by-spec read, including both models, delivery and offers, see our Plunge infrared sauna review.

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Light, glow and what to think about

Incandescent towers produce visible light as well as infrared, since NASA notes that heat lamps often emit both. That raises a few practical points.

Brightness. Lamp towers glow, and in a small cabin that may feel pleasant or too bright, depending on you. Plunge lists 360-degree chromotherapy LED lighting, but the pages do not describe how the tower glow interacts with it.

Electrical field concerns. Plunge states a near-zero EMF rating (0.1 mG per its Trifield reading). That is Plunge's own statement, not an independent verification. Our low EMF infrared sauna guide explains the unit, how a reading is taken and how to question a claim like this one.

What to ask a seller about "full spectrum"

Use this list on any sauna you consider, including Plunge's.

  1. Which heaters produce the near and mid infrared? Ask for the heater type and how many there are.
  2. What do the panels emit? For Plunge, the pages name far infrared.
  3. What is the power of each heater? Total wattage tells you the draw from your wall, and heater wattage tells you more about heat output than any label.
  4. Has anyone measured the output by wavelength band, and who? A third-party measurement carries more weight than a brochure. If none exists, the seller should say so.
  5. What is the EMF figure, where was it measured and at what setting? Ask for the meter, the distance and the heater setting.
  6. What does the warranty cover on heaters versus electronics? Per Plunge: 5 years on cabinetry and heaters, 2 years on electronics and controls, 1 year on glass and power supplies, with optional 2-year extended coverage, as read.
  7. What is the trial or return policy? The Plunge pages we read did not state one. Read the policy at checkout before you pay.

Safety basics for any infrared sauna

Heat is a stress on your body, so a few rules apply regardless of the wavelength mix.

Cleveland Clinic advises staying hydrated, bringing water in with you and leaving the sauna right away if you feel dizzy or nauseated. For beginners it suggests starting at a low temperature for five to 10 minutes. It says experienced users should keep sessions to a maximum of 20 to 30 minutes.

It also recommends checking with a healthcare provider before starting if you are pregnant, planning to conceive, have multiple sclerosis or have other existing medical conditions. If you take medicines that affect blood pressure, heart rate or fluid balance, or you have heart or circulation problems, ask your doctor first.

None of this changes with "full spectrum." Start at the low end of the control range, because we have no published breakdown of how the towers add to the heat you feel.

Who Plunge suits and who should look elsewhere

Plunge may suit you if:

Look elsewhere if:

Delivery is standard curbside for $250 in the lower 48 states, per Plunge, as read. The pages also list a $500 automatic discount, a complimentary extended warranty ($399 value) and 0% APR financing for up to 36 months through Bread Pay, subject to credit approval, as read on 2026-10-28. Offers change, so confirm today's terms on Plunge's pages.

If you are comparing the market more widely, our pick of the best infrared home sauna explains how we define "best" and what we compared.

Key takeaways

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FAQ

What is the difference between near, mid and far infrared?

They are three zones of the infrared band, split by wavelength. Caltech's IPAC lists near infrared as roughly 0.7 to 1 up to 5 microns, mid infrared as 5 up to about 25 to 40 microns and far infrared as about 25 to 40 up to about 200 to 350 microns. The boundaries are not agreed upon.

Is "full spectrum" an official sauna category?

We did not find a standard or official definition for it. Sellers use the term, and they do not all use it the same way. Ask for the heater list.

Is a full spectrum infrared sauna better than a far-infrared one?

We cannot say. The label describes a design choice, not a ranking, and we have not used any of these saunas. Our infrared sauna benefits guide covers what the research shows about infrared sauna use in general.

Does Plunge say its sauna is full spectrum?

Per Plunge, its saunas use far-infrared panels plus full-spectrum incandescent towers. We read that on 2026-10-28. The pages did not give a wavelength or power breakdown.

Do full spectrum saunas have higher EMF?

We did not find a source that answers this for sauna heaters in general, so we do not claim one. Plunge states a near-zero EMF rating (0.1 mG per its Trifield reading). See low EMF infrared sauna.

How hot does a Plunge sauna get?

Per Plunge, up to 160 degrees Fahrenheit for the Standard and up to 175 degrees Fahrenheit for the Pro. Those are maximums, not suggested settings. Cleveland Clinic quotes 110 to 135 degrees Fahrenheit as a typical infrared range.

Can I use an infrared sauna if I have a health condition?

Ask your doctor first, especially if you are pregnant, take medicines or have heart, blood pressure or other medical conditions.

Is there a trial or return policy?

The Plunge pages we read did not state one. Read the policy at checkout before you buy.

Sources