Guide
thermalmonitord is a process name
thermalmonitord is the daemon that checks thermal sensors. You cannot order a part by that name. The rest of the log tells you which rule Log is allowed to use.
Watchdog, and no missing sensor
One shape is a watchdog timeout, no successful check-ins from thermalmonitord, and no missing-sensor list. Log's rule for that shape follows the public iFixit note and treats it as a software failure in most cases, including early iOS 16.
The printed confidence is medium. The step in that rule is to back up the phone and restore iOS. If the phone panics again, read the new log before you open it.
Watchdog plus a sensor name
The other shape also names a missing sensor. mic1, prs0, or another name is the more specific clue, and that sensor's rule is the one to read.
thermalmonitord missing a check-in can be how the watchdog reports that a sensor never answered. The daemon name alone is not a thermal camera, a battery, or a charge port.
Do not invent a part from the word thermal
Heat-sensor maps are not one flex across iPhones. If the log has no missing sensor and no SMC code, stay with the software step above.
If the log has an SMC code, use the SMC guide for that product string. Heat, liquid, and a swollen battery are bench checks. Log cannot assign a part from the daemon name alone.