You know your body temperature is supposed to be 98.6 degrees. It’s a number you don’t want to see go up because when it does, it’s usually a sign something’s wrong.
But what if a deliberate rise in core temperature could actually support your immune system, improve circulation, and even help you sleep better?
Researchers at the University of Oregon recently set out to explore this question by comparing the effects of what they call “passive heat therapies.” In other words, they wanted to understand how the health benefits of hot tubs and saunas compare.
What they found: Hot tubs and saunas both can support your overall well-being. But one modality offers a stronger effect on core temperature, which triggers many of the benefits linked to heat therapy.
Raising your temperature on purpose
In the University of Oregon study, researchers observed 20 healthy adults: 10 men and 10 women, all regular exercisers. Each participant tried three different heat therapies on separate days: a traditional dry sauna, a far-infrared sauna, and a hot tub.
Before, during, and after each session, the team measured core body temperature, heart rate, blood pressure, and a range of health markers related to inflammation and immune function.
All three options increased body temperature and triggered a change in cardiovascular function. However, hot water immersion raised core temperature the most. Researchers say this increase in temperature helps with increasing circulation, reducing stress, improving sleep, and supporting your immune system.
The health benefits of hot tubs
Soaking in a hot tub does more than help you relax. It also triggers a host of health benefits, helping you to move better, feel better, and live a healthier life.
Improved vascular function
As your body heats up, your blood vessels widen and blood flow increases. This makes it easier for your heart to pump blood, supporting cardiovascular efficiency. Over time, regular heat exposure may improve endothelial function, which plays a critical role in heart health and blood pressure regulation.
Reduced inflammation
Heat exposure stimulates heat shock proteins, which help protect your cells from stress and promote repair. These proteins are also linked to a reduction in chronic inflammation, which is associated with arthritis, heart disease, and Type 2 diabetes. Some research also shows a temporary decrease in inflammatory markers like C-reactive protein following passive heating exposure.
Enhanced immune response
Raising your core temperature mimics a mild fever response, which can stimulate immune cell activity. Studies suggest that heat exposure increases the circulation of white blood cells and other immune system components, helping the body respond more effectively to illness or infection.
Stress relief and better sleep
The warmth of a hot tub activates the parasympathetic nervous system, which promotes relaxation and helps regulate stress hormones like cortisol. After you exit the water, the slight drop in core temperature can also help signal to your body that it’s time to sleep — making it easier to fall asleep and stay asleep.
Added benefit: hydrotherapy
Unlike saunas, hot tubs also offer hydrotherapy, which combines heat with the therapeutic power of water. Massage jets help reduce muscle soreness, while the buoyancy of the water can ease pressure on joints and support faster recovery. This makes hot tubs especially beneficial for people managing chronic pain, soreness, or stiffness.
What about the benefits of saunas?
While hot tubs had the strongest effect on core body temperature in the study, both types of sauna still delivered meaningful results.
In a traditional dry sauna, the air temperature can be as hot as 200 degrees. Your body heats from the outside in, and you begin to sweat, helping your body regulate internal temperature and flush out toxins.
Infrared saunas, on the other hand, work differently. Rather than heating the air around you, they use infrared light to gently warm your body directly. The air stays cooler, but the infrared wavelengths can penetrate more deeply into muscles and tissues.
Both types of saunas have been associated with increased heart rate and circulation, lower stress levels, improved skin tone and appearance, and support for detoxification through sweating. Some long-term studies have also linked regular sauna use to a reduced risk of cardiovascular disease and improved longevity.
Hot tub or sauna: Which should you choose?
There’s no one-size-fits-all answer. Both hot tubs and saunas offer important health benefits and support overall wellness in slightly different ways.
A hot tub might be the right choice if:
- Full-body immersion sounds like the most relaxing way to unwind
- You’re looking for the greatest increase in core body temperature for therapeutic benefits
- Hydrotherapy features like massage jets and buoyancy would support your recovery
- You’re managing joint pain, muscle soreness, or chronic inflammation
- You want to create a relaxing space for family connection or outdoor entertaining
- Enhancing your backyard with a year-round wellness feature is part of your long-term plan
A sauna might be the right choice if:
- A dry heat experience feels more comfortable or appealing
- Quick, convenient sessions fit better into your routine
- Sweating to support detoxification and skin health is a priority
- Space is limited, or you prefer an indoor heat therapy option
- You want a calming spot to unwind and reduce daily stress
- Creating a dedicated wellness area in your home is part of your lifestyle goals
Whether you’re soaking or sweating, the most important thing is to choose a heat routine that you can follow consistently. Regular passive heat therapy can help your body adapt and support its natural healing and recovery processes.
Supporting your wellness at home
You don’t need a gym membership or spa appointment to experience the benefits of passive heat therapy. With a Master Spas hot tub or Sweaty GOAT Sauna, you can bring these proven wellness tools into your daily routine — without leaving home.
Hot tubs
Master Spas hot tubs are designed to maximize comfort and therapeutic benefits. Features like powerful massage jets, biomagnetic therapy, and ergonomic seating make it easy to prioritize your wellness every day.
Sweaty GOAT Saunas
If you prefer the therapeutic experience of an infrared sauna, Michael Phelps Sweaty GOAT Saunas fit a variety of lifestyles and space requirements. These saunas feature full spectrum infrared therapy, combining near, mid, and far wavelengths to warm the body from the inside out. A hybrid heating system blends light-based and traditional elements to deliver a deep, consistent heat that promotes relaxation, detoxification, and recovery.
By making time for heat therapy at home, you give your body the opportunity to warm up, slow down, and naturally support its own resilience.