Application
Heat strain is a composite trend
Heat strain cannot be reduced to one sensor. A credible wearable approach combines heart-rate elevation, respiration change, skin temperature deviation, activity context, and perfusion trend behavior.
Why multisensor context matters
High heart rate alone may be exercise, stress, heat, or motion artifact. Temperature alone may be environment or skin contact. Combining signals improves interpretation but still requires confidence gates.
User output
SciFold should classify trend states such as Normal, Watch, Elevated, and High with clear non-diagnostic language.