A wet sauna

The word sauna is actually Finnish for bath, so it is not surprising that many people think of a sauna as a wet experience. However the environment within a sauna should be anything but wet – unless that is water is added.

A sauna works by containing very hot air (up to 200 degrees Fahrenheit) and by maintaining a very low humidity, typically less than 4% or 5%.

In other words saunas are hot and dry and not damp or wet.

The reason for a sauna being so dry is so that the human body is able to sweat profusely. The lower the humidity, the easier it is for the body to release sweat and for the atmosphere to absorb it. Consequently having a sauna room with a moist and high humidity environment would be contrary to the way in which a sauna works.

The exception

There is one exception to this hot and dry sauna environment and this is when a small amount of water is splashed over the sauna heater’s hot rocks. (Note, this is not possible with an infrared heater.)

The rocks are normally on the hot plate of the (electric) heater and as the water hits them it is instantaneously converted into vapour creating what some people describe as a steam shock.

The effect of adding this water, and having it vaporised, is to cause a dramatic but short term increase in the humidity of the sauna. i.e. The sauna takes on a much wetter atmosphere.

This extra moisture increases the humidity by 20% to 30% and the upshot of this is that the sauna room feels much hotter than it did prior to the addition of the water. The effect is immediate, however it dissipates fairly quickly as the extra moisture is absorbed into the sauna room’s timber lining.

Some sauna users do not like this wet sauna sensation. For one thing it makes the sauna feel much hotter and it also reduces the speed at which sweat is evaporated off the body. This can lead to a hot and sticky sensation which not everyone finds pleasing.

The traditional way of enjoying a sauna experience is to take short sauna session of 20 to 30 minutes followed by a period of rest (and often a cold shower) outside of the sauna room. Those who enjoy a wet sauna will splash water on the heater’s hot rocks during some of these sessions.

A sauna, be it hot or wet, is completely different to a steam shower, details of which you can find here steam shower.

To find out about the many benefits of taking a sauna you can take a look at this sauna benefits page.