The hot exercise room at Spinal Fitness Health and Wellness Center in Kennewick, WA uses a low-EMF Sauna Fix radiant tent that emits light and radiant heat from 550 to 3000 nm and reaches a maximum of 155°F, about 68°C. A 2018 systematic review of dry sauna bathing by Hussain and Cohen of RMIT University, in Evidence-Based Complementary and Alternative Medicine, describes the body’s response to that kind of heat: “Intense short-term heat exposure elevates skin temperature and core body temperature,” with “increased heart rate, skin blood flow, cardiac output, and sweating.” In the hot exercise room a member exercises under the lamps while exposed to that heat. Members hold 24/7 access through a door code once training is complete, and every Thursday from 2 to 6 PM the center is open to new visitors for a free session.
Radiant heat reaches the skin first
The Hussain and Cohen review places infrared saunas at 45 to 60°C, 113 to 140°F, against 80 to 100°C, 176 to 212°F, for traditional Finnish saunas, with similar exposure times of 5 to 20 minutes. The room’s 155°F maximum, about 68°C, sits above that infrared range and below the Finnish range. Radiant heat warms the body from the lamps directly, so the room needs no long preheat: the Sauna Fix instructions state that the incandescent bulbs “begin producing radiant heat immediately” and the tent keeps warming during the session. The Spinal Fitness book by Eileen Durfee describes Sauna Fix as near-infrared, distinct from a standard far-infrared sauna.
What the near-infrared light does
The Spinal Fitness book names photobiomodulation through cytochrome c oxidase as the action of near-infrared light. A 2017 review in AIMS Biophysics by Michael R. Hamblin identifies cytochrome c oxidase, an enzyme in the mitochondria, as the primary light-absorbing molecule for red and near-infrared light, and states it absorbs “well into the NIR region (up to 950 nm).” The same review states that near-infrared penetration depth “is maximal about 810 nm, and at longer wavelengths water becomes an important absorber,” with a water absorption peak at 980 nm. The room’s 550 to 3000 nm output spans both ranges: the shorter near-infrared band that the review links to cytochrome c oxidase, and the longer wavelengths that water in the tissue absorbs.
Response 1: skin temperature and skin blood flow
Hussain and Cohen list higher skin temperature and higher skin blood flow among the first responses to sauna heat. The Sauna Fix instructions call for turning about 90 degrees every few minutes, front, right side, back and left side in sequence, which the instructions state “creates more balanced radiant exposure and supports the side-to-side blood-shunting effect.”
Response 2: heart rate and cardiac output
The review lists higher heart rate and higher cardiac output, the volume of blood the heart pumps per minute, as standard responses to sauna heat. The center’s 24/7 Fitness page calls exercise in radiant heat “an intense training environment” and directs members to build duration and effort gradually rather than treating it like an ordinary room-temperature workout.
Response 3: sweating and mineral loss
Hussain and Cohen list sweating among the responses to sauna heat, and sweat carries minerals out with the water. The Spinal Fitness book’s instruction after sweating is to “replace sodium, potassium, magnesium, and trace minerals – not only water.” The Sauna Fix instructions add that longer, heavier-sweating sessions may need more fluid and electrolytes, and towels are used to wipe sweat through each session.
Response 4: core temperature
Hussain and Cohen state that intense heat exposure elevates core body temperature as well as skin temperature. The Sauna Fix instructions state that some people sweat heavily within minutes while others take longer to develop an efficient sweating response, and that “a person who does not sweat well can still overheat.”
Session facts
A hot-room session runs 20 to 40 minutes, standing or sitting. Before first use, members complete a safety screen and receive hydration guidance, and the center’s page states that heat exposure is not appropriate for some people with cardiovascular conditions, impaired heat tolerance or medication-related risk. The room is offered for fitness and general wellness, and individual experiences vary.
Visiting the center in Kennewick
The hot exercise room is included with membership, along with the near-infrared saunas, first come, first served, 24/7. The free Thursday session for new visitors, 2 to 6 PM, rotates 1 service per week among the BioCharger NG, the 7 Wave light panel, Brown’s Gas, PEMF and the hot exercise room, where the free session runs up to 40 minutes. Spinal Fitness Health and Wellness Center is at 214 E. Albany Ave, Building E101, Kennewick, WA 99336, serving Kennewick, Pasco, Richland, West Richland, Benton City and Walla Walla. Call or text 509-670-9713. Eileen Durfee has worked in the health field since 2010 and is a NASM Certified Personal Trainer.
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This article is for educational purposes only. The hot exercise room is offered as a fitness service for general well-being.
