The Difference Between Red Light Therapy and Saunas
Saunas and red light therapy are two clinically-proven treatments that offer a range of natural health benefits. They work well as complementary therapies, but rely on very different biological mechanisms of action to produce those health benefits. Recently, there has been an increasing trend in using both therapies simultaneously to reduce the duration of a treatment. While this may seem like a smart way to save time, does it make sense from a biological perspective?
This short article breaks down the key differences between red light therapy and sauna therapy, focusing on how they work, the benefits, and why we believe these therapies may be best performed individually.
How a Sauna Works
The purpose of a sauna is to deliver enough heat to raise your body’s core temperature. Almost every sauna today accomplishes this by either using traditional convection heat methods, or by emitting far infrared wavelengths.
Convection Saunas: Convection saunas originated in Finland dating back thousands of years. They rely on the principle of warming the air inside the sauna to create a heat experience. Typically, an electric stove filled with lava stones, or a wood stove with hot embers is used to generate the heat. With temperatures averaging between 160 and 200 degrees Fahrenheit, these saunas envelop the individual in a warm atmosphere. As the heated air contacts the skin, the core body temperature gradually rises.
Infrared Saunas: More popular in recent years, infrared saunas don’t heat the air, but actually heat the objects inside the sauna space. Infrared saunas use charcoal, carbon fiber, or other types of emitting surfaces to deliver infrared heat. While many saunas are marketed as providing “full spectrum” infrared wavelengths, the vast majority of research supporting the health benefits of saunas is tied directly to the temperature, humidity, and treatment time under which your body is exposed to heat.
The most effective wavelengths in terms of generating heat, are in the far infrared spectrum. High-quality saunas utilize far infrared technology that delivers IR-C wavelengths. IR-C is a range of light that falls between 3um to 1mm. This spectrum of light is efficient in generating heat within the body by influencing water molecules located deep in the tissue.
Health Benefits of Saunas
All saunas work by inducing thermal stress on the body. This idea stems from the concept of hormesis, where harmful stimuli at low doses may actually have beneficial effects. 
The induction of heat stress in the body leads to various biological reactions such as increased heart rate and perspiration. Adequate heat exposure can trigger the activation of the body's heat shock factors (HSFs) responsible for stress regulation. Additionally, heat stress influences protein metabolism, prompting the activation of specialized proteins like heat shock proteins (HSPs). HSFs and HSPs are pivotal in facilitating long-term health advantages, particularly in the cardiovascular system, resulting in an overall improvement in exercise capacity.
While the majority of benefits from saunas are related to increased cardiovascular function, other studies have demonstrated benefits like improvement in chronic fatigue, decreased depression, and helping your body clear toxins. 
How Red Light Devices Work
A red light therapy, or Photobiomodulation (PBM) device works by emitting energy that falls within the visible Red and Near-infrared (IR-A) spectrum.
Light Emitting Diodes (LEDs) are the primary source of light, with both coherent and incoherent light properties used. The light output intensity can be improved using an optical lens, which helps focus the light in a more narrow range depending on the device type. The light energy emitted in this range does not generate heat, thereby avoiding an increase in the body's core temperature. Instead, the energy is delivered non-invasively and absorbed by the cells' mitochondria, influencing the cells' ability to produce energy through ATP production. The physical size of a red light therapy device varies according to the size of the light emitting surface. This is because, to effectively apply the light on the body, the light should be positioned in front of the body while directly facing the light emitting surface. The distance between the device's surface and the body plays a significant role in determining the amount of light intensity received while using the device.
Health Benefits of Red Light Devices
At Joovv, we believe that red and near infrared light impacts every user differently. Based on the science, we believe the benefits from use are best understood systemically and for this reason we provide generalized treatment guidelines. Even though each one of us is capable of absorbing red and infrared light, our body is the ultimate decision maker on how the light will be used. To learn more about the systemic effects of Red Light therapy check out this article.
Why You May Want to Keep Sauna and Red Light Therapy Separate
Saunas and Red light therapy are two effective therapies that support balance and health, but do so in very different ways. To summarize, saunas generate heat to induce stress stimuli while red light devices emit energy to support energy production and recovery. As their action mechanisms differ significantly, it's best to use them independently. Trying to create stress and energize/recover at the same time wouldn't be ideal. If you wish to combine them, it would be best to use a sauna first, and follow up with a light therapy session after to help your body recover from the stress. While both therapies are effective on their own, more research is needed to determine their overall efficacy when combined.
Sources and References:
 Michael R. Hamblin. Traditional or Infrared Saunas and Photobiomodulation: What Do They Have in Common?. Photobiomodulation, Photomedicine, and Laser Surgery.Sep 2022.595-596. http://doi.org/10.1089/photob.2022.0078
 Crinnion WJ. Sauna as a valuable clinical tool for cardiovascular, autoimmune, toxicant- induced and other chronic health problems. Altern Med Rev. 2011 Sep.