Traditional Saunas

Traditional saunas originate from Finland and are heated using either electric or wood-fired heaters. Electric heaters often contain coils, and many are designed to have rocks on the top. Unlike steam saunas, it maintains a low humidity level, resulting in a dry and intensely warm environment that promotes sweating and relaxation. 

Despite the dry name in the descriptor, it's common to have rocks on the heater which users can then pour water over top. This will create a small amount of moisture and humidity in the sauna. It's still a "dry" sauna or some manufacturers call it a "wet / dry" sauna.