Have you ever jumped in a cold lake and felt instantly awake? Or have you sat in a hot tub and thought that you could fall asleep right then and there?

As cold plunges are becoming more popular, more information is becoming available about the health effects that cold and hot water have on our bodies.  

Cleveland Clinic says that hot tubs can be good relievers of stress because they can release physical tension in the body. The heat from hot tubs expands your blood vessels and increases blood flow, which can loosen tight muscles and decrease blood pressure. The buoyancy you experience by just being in water can also relieve joint pressure, which can help with diseases like arthritis. 

A study done in Japan, mentioned by Harvard Health, showed that daily baths decreased the risk of cardiovascular disease by 28%, and the risk of a stroke by 26%. The Cleveland Clinic also says that hot tubs can be heart healthy, as the decreased blood pressure can provide temporary relief from the hypertension. 

Taking a hot bath or sitting in a hot tub a few hours before going to bed can also improve your sleep. Before falling asleep, your body naturally lowers its temperature. By heating up your body and allowing it some time to cool down, you simulate that temperature drop. This can help you feel more relaxed before going to sleep, according to the Cleveland Clinic. 

Both Harvard Health and the Cleveland Clinic don’t recommend prolonged hot tub sessions for people who are pregnant and those who have low blood pressure or other serious heart conditions. Hot water can also trigger seizures, so people with disorders like epilepsy should avoid hot tubs. 

A cold plunge consists of submerging your body in cold water with a temperature between 50 to 59 degrees Fahrenheit for 10 to 15 minutes. For reference, public pools are normally kept at temperatures of 78 to 82 degrees Fahrenheit. According to Permanente Medicine, submerging for longer than 15 minutes does not increase benefits of a cold plunge, and it can instead increase possible risks.

Cold plunges can prevent the muscle soreness you feel a day after an intense workout. Harvard Health states that there isn’t enough information to prove this, but Permanente Medicine says that the cold water causes blood vessels to constrict, which slows blood flow and reduces inflammation of the muscles. Plunging into cold water can also activate brown fat, which is responsible for keeping the body warm. This activation can help burn calories and speed up metabolism. 

Permanente Medicine says that the body releases endorphins as an initial response to the cold water, which can boost your mood. Similarly, a study made by Lifestyle Medicine at Stanford says that routine cold plunges can reduce levels of cortisol, a stress hormone. 

Harvard Health also says that cold plunges can also promote the body’s rest and recovery response by enhancing parasympathetic activity. But they don’t recommend cold plunges for those with heart disease because the adrenaline spike they cause can disrupt the heart’s rhythm.

You can experience a hot water plunge in hot tubs, which can be found in public facilities like gyms. Another, less formal opportunity occurs in hot springs, which can reach temperatures over 100 degrees Fahrenheit. 

Cold plunge facilities can also be found at certain gyms. A cold body of water that allows swimming is another option, or you can make your own by putting a few bags of ice in your tub at home, but make sure you check the temperature for those two options.

If you want a more tame cold water experience, you can start by taking a cold shower, or start with a lukewarm one and end it cold.