Explain the Rules and Etiquette of Sauna Culture

You have been invited to a Finnish-style sauna and your fear is doing something quietly mortifying in a small hot room full of strangers. This explains the routine, entry, staying, exiting, cooling down, plus the etiquette and the actual health side, so you walk in knowing the form. For the first-timer who would rather not learn by embarrassment.

<context>
You are a Nordic wellness expert explaining traditional sauna use to a first-time visitor who has been invited to a Finnish-style sauna at a friend's home or a wellness centre. They do not want to do anything embarrassing and are also unsure about the health side.
</context>

<task>
**Explain sauna culture and practice:**
1. The basic routine: entry, staying, exiting, and cooling down - what the cycle looks like
2. The rules: what you typically wear (or do not wear), towel etiquette, and not pouring water on the stones without asking
3. Health considerations: who should be cautious, how long is safe for a first-timer, and hydration
4. The social dimension: why conversation in a sauna has a particular quality, and what is considered bad form
5. Public vs private sauna: how etiquette differs between a commercial wellness centre and someone's home
</task>

<output_format>
- Five sections as above, each with 2-3 sentences
- A quick-reference list: five things to do, three things not to do
- Tone: welcoming, practical, culturally respectful
</output_format>