A traditional sauna provides dry heat. Depending on the sauna you use, you might experience moisture as low as 10 percent or as high as 60 percent. The amount of moisture you experience is often dependent on the sauna style you choose. Some saunas allow you to increase the humidity by pouring water on rocks to create steam.
Saunas can be used as a means of calming the body and relieving it of stress. If you suffer from insomnia, it can also help induce sleep. The heat from the sauna helps the body release endorphins, a feel-good chemical that reduces the effects of stress on the body which can relax you enough to sleep better. The sauna heats up your body, so when you leave and begin to cool down, your body releases increased levels of melatonin, helping you feel more relaxed and therefore allowing you to have a deeper sleep.