The Science Behind the Heat
Explore the science of heat and light. This collection brings together studies and reviews on sauna bathing and photobiomodulation, with clear summaries and links to the original research. Learn what researchers found and how the study setting shapes the results.
Sauna heating and photobiomodulation are different interventions. The Finnish observational studies below concern traditional hot-air sauna bathing, while other papers examine dry sauna protocols, clinical whole-body heating or targeted light treatment. These studies provide general research context; they are not clinical tests of Heavenly Heat products, and individual outcomes vary.
Sauna bathing studies
Six studies and reviews on traditional Finnish, dry and clinical whole-body heating.
- Laukkanen T et al. (2015)
Finnish sauna and cardiovascular health
A long-term study of 2,315 middle-aged Finnish men associated more frequent traditional Finnish sauna bathing with lower cardiovascular and all-cause mortality. This observational finding supports further research; it does not establish cause and effect or demonstrate equivalent results from infrared saunas or Heavenly Heat products.
- Laukkanen T et al. (2017)
Finnish sauna and memory outcomes
More frequent traditional Finnish sauna bathing was associated with fewer dementia and Alzheimer’s diagnoses during follow-up. This analysis used the same Finnish male cohort as the cardiovascular study, adding a different outcome rather than independent replication. It does not establish prevention or test infrared saunas or Heavenly Heat products.
- Laukkanen JA et al. (2018)
Finnish sauna research overview
This review brings together observational and intervention research on Finnish sauna bathing and cardiovascular and other health outcomes. It explores possible physiological explanations and areas of uncertainty. Its findings depend on the populations and heating protocols studied and do not establish equivalent effects for every sauna type.
- Kunutsor SK et al. (2018)
Finnish sauna and stroke research
In 1,628 Finnish men and women, more frequent traditional Finnish sauna bathing was associated with lower stroke incidence during follow-up. The observational results identify a research connection rather than proving prevention. They do not show that infrared saunas or Heavenly Heat products provide the same outcomes.
- Hussain J & Cohen M (2018)
Dry sauna research review
This systematic review examined 40 studies of repeated dry sauna use, including traditional Finnish and infrared approaches. It identified potential health benefits, but many studies were small and protocols varied. Stronger evidence is needed to establish suitable protocols, the extent of adverse effects and which populations may benefit.
- Janssen CW et al. (2016)
Clinical heating and mood research
A small randomized trial found greater reductions in depression scores after one supervised whole-body hyperthermia session than after a sham procedure. The specialist clinical setting and protocol differ from ordinary home sauna use. This study does not establish that a Heavenly Heat sauna treats depression.
Read the publisher correction alongside this study. It updates the statistical-analysis description and Figure 2; it is a correction, not a retraction.
Photobiomodulation studies
Six reviews and studies on red and near-infrared light, from cellular mechanisms to targeted treatment.
- Hamblin MR (2017)
Light and inflammatory responses
This review examines how red and near-infrared light may influence cellular energy and inflammatory responses. Laboratory and selected clinical findings help explain the research, while effects depend on the tissue, condition and light dose. The review does not establish a general longevity benefit from a Heavenly Heat product.
- Hamblin MR (2016)
Light applied to the head
This review describes preclinical and early clinical research on light applied to the head, including studies of brain disorders. Its targeted protocols differ from general exposure to a red light panel or sauna cabin. The findings help frame further research rather than establish a benefit from every light device.
- Salehpour F et al. (2018)
Brain photobiomodulation review
Researchers explore how brain-directed light may influence neuronal energy and cellular responses. This narrative review covers preclinical and clinical evidence and explains why treatment location, light dose and tissue penetration matter. These delivery limits prevent assuming the same effects from a general-purpose home light panel.
- de Freitas LF & Hamblin MR (2016)
Proposed cellular light mechanisms
This review explains proposed pathways linking light absorption with cellular energy and signaling. It provides a foundation for understanding photobiomodulation, while clinical effects require evidence from the relevant treatment and device. Its proposed mechanisms are not a clinical test of a Heavenly Heat product.
- Wunsch A & Matuschka K (2014)
Light and skin appearance
Treatment groups in a controlled study showed improvements in skin appearance, surface roughness and measured collagen density after 30 sessions. These results relate to the specific light sources, settings and schedule tested. They should not be assumed to apply to a different commercial light device.
- Cassano P et al. (2016)
Brain-directed light and mood
This review discusses early depression research using brain-directed photobiomodulation. It describes an experimental approach and calls for larger randomized trials to establish safety and effectiveness for this condition. It does not establish that a home red light panel or sauna treats depression.
Questions about the research or a sauna?
Our U.S.-based team knows every model we build. Call, email or book a free consultation.
- Customer Support
Rachel & Michael
Available 8:00am–8:00pm EST, Monday to Friday.
- Email
Write to us
Questions about an order, delivery or your installation? Send us a message.