And of course here is nostr:nprofile1qqsw3znfr6vdnxrujezjrhlkqqjlvpcqx79ys7gcph9mkjjsy7zsgygpz3mhxue69uhhyetvv9ujuerpd46hxtnfduq3vamnwvaz7tmjv4kxz7fwwpexjmtpdshxuet5scvysa excellent article on the subject:
https://dev.primal.net/nvk/An-opinionated-guide-to-Sauna-4ts6ca.
And another good resource:
https://saunologia.fi/in-english/finnish-sauna-essentials-part-5/