Do Hot Tubs Increase Brain Function?

The healing powers of warm water are well established—from the ancient Greek physician Hippocrates who recommended water therapy to his patients, all through the rise of the Roman Empire, baths were considered necessary to maintain physical and even mental strength. The ancient civilization of the Incas in South America respected water as a life force and would use hot springs to rejuvenate themselves regularly.

Even though sometimes modern medicine moves away from ancient wisdom, this is not necessarily the case with the idea of hot water therapy, particularly in light of a recent study that shows hot water may significantly increase brain function.

Do hot tubs increase brain function?

A recent study performed examining middle-aged women suffering from fibromyalgia experimented by having women exercise in both warm and cool pool temperatures. The study came to the conclusion that not only did exercising in the warmer water three times a week for 16 weeks was a good way to treat the women diagnosed with FM, but it led to improved cognitive function of those same women. They also had a higher pain tolerance and had a reduction in pain symptoms.

One of the reasons warm water is so effective at soothing our aches and pains is that it increases blood flow in the body. Naturally, this means that the blood flow to the brain is also improved. Those test subjects being evaluated on their cognitive skills after a soak in the hot tub are showing improved brain function.

Another reason for this improvement is that the exposure to heat increases the delivery of oxygen to the pre-frontal cortex, resulting in a pre-frontal cortex that stays oxygenated longer and is able to function at a higher level. When heat is present in water that surrounds the body, the core temperature surges. The body responds to this increase by sending more oxygen rich blood to the brain and helping it react quicker and with increased mental acuity.

Alternatively, being exposed to cold water (55° F and below) can lead to a marked reduction in cognitive abilities. Subjects in a Kent State study were tested before and after soaking in cold water and had a slowed reaction time and the opposite reaction than those who soaked in warm water.

Does this mean we always have increased brain function when we’re hot?

Actually, this theory does not extend to hot weather. The United States army conducted a study that looked at the effects of outside air temperature on its soldiers in the cold as well as the heat. Turns out, soldiers did not respond well to cognitive tests at temperatures below 50° or hot weather over 90°. It only seems to hold true when the body is heated radiantly via warm/hot water.

Treating Brain Injuries

In relation to helping our brains function better, Dr. Bruce Becker has found that hot water therapy can help people who have Traumatic Brain Injury or TBI. As a physician who has specialized in rehabilitation and psychiatry and has headed the rehab centuries of two separate hospitals, Dr. Becker has spent time researching how to help those with TBI.

Becker became interested in the use of aquatics after working first with Olympians. Said Becker, “We have done a lot of work with hot tubs, and my previous work with TBI patients has given me a significant reason to believe that warm water immersion may indeed have real benefit for the management of brain injury.”

The reason behind this improvement is that in addition to the oxygenation of the frontal cortex of the brain, the central nervous system undergoes a regulation of stress responses. That response that can be triggered by hot water and has been proven to show improvement in memory, moods, and general brain function.

Warm water can also lead the brain to release a chemical called BDNF (brain derived neurotropic factor). This is a protein that the body produces that aids in nerve and brain regrowth and restoration. It’s also a protein that is released during exercise.

Other Mental Benefits of Hot Water

• TBI patients who spent time in the warm water showed improved speech function, less agitation, and improved sleeping patterns. They required less medication throughout the day and needed less pain management.


• The combination of improved blood flow and decreased stress and pain are a huge health benefit.


• Immersion in hot water has been shown to elevate the bather’s mood for several hours after soaking that is very similar to a runner’s high.


• Test subjects have been given regular warm water therapy and have seen a reduction in anxiety that needed less management through prescription drugs.


• Hot tubs may be on the forefront of autism-related research—there’s been considerable evidence that suggests that inflammation may play an important role in mediating neuropsychiatric symptoms like autism.


• Many children with autism showed improvement to their behavior when they are in water around 102° had noticeably diminished symptoms after being in the water for 30 minutes. Their guardians also saw improvements in both social communication and repetitive behaviors during that time.