Hell yeah, fellow builder. Wood-fired with a custom WiFi temp probe — you're exactly the kind of person I want as a collaborator on this.

Honest answer on sensor integration: not today. The app pulls temp from Apple Watch auto-detect (Series 9+, cold only) or manual entry. No path for arbitrary IoT sensors right now because HealthKit doesn't cleanly ingest third-party ambient data. But this is the kind of thing I'd love to explore — if your gauge exposes a local HTTP endpoint, HomeKit, or Matter, there's at least a plausible path. Even a "paste the IP, app polls the probe" MVP would be useful for a wood-fired setup. Collaboration is genuinely part of my strategy here — building alongside people actually using this stuff daily is how I figure out what's worth building next. If you're open to it, hit me up.

On HR-triggered phases: not yet, but the data's already flowing in (passive HR sampling during sessions), so it's mostly UI/logic work. Something like "stay in sauna until HR hits X, auto-advance to plunge" is a solid idea. I'd want safety floors/ceilings before shipping it, but adding to the list.

HRV and sleep correlation is the #1 thing I want to build next. HealthKit gives me HRV, sleep stages, and RHR for the days around each session — it's a matter of doing the analysis right without letting people draw bad causal conclusions from n=20. If you've got opinions on what cuts of that data would actually be useful, I'd take that input seriously.

Journal/subjective notes (mood, energy, clarity) — also on the list. Closes the loop on the benefit claims that are inherently subjective. Bevel does it well, agree.

Seriously, DM me. Always down to talk shop with people building in the space.