Mikkel Aaland's 1978 book Sweat is a good read. He has a neglected website, which is excusable for the fact that he is also a pioneer in digital photography, has just this year released a new book on sauna construction, How to Build Your Own Sauna and Sweat, and is working on a new PBS documentary based on his original book. Perhaps the stained and well-worn library copy I read was an early edition, but I noticed that the text had several paragraphs out of sequence and several pages seemed to be completely missing (despite following numerical order). The information that is there is very good however, and it is evident that Aaland is dedicated to his subject material having done a lot of original research in the field.
Several of the descriptions of the sounds and sensations one has in a sauna were very good. He quoted Seven Brothers, by Aleksis Kivi: “Timo threw water on the heated oven until the blackened stones heaped over it cracked with a noise like rifle fire”. Yes, that is what it sounds like, and the resulting loyly feels like heaven on your skin. After reading the book, I wanted to get my own vihta and take a sauna! Until you have taken several different saunas, it is hard to appreciate the different qualities that they can have. A sauna is much more than a hot room. The quality of heat, if one can speak of it in this way, can be excellent or unbearably harsh. Maybe there is something to the idea of negative ions (that I come across frequently in descriptions, but remain skeptical of). There are more books awaiting my review, but my attention must be averted to other matters for the mean time.