Wearable‐Derived Diurnal Alignment Between Physical Activity and Device Temperature Predicts Future Disease and Mortality Risk

ABSTRACT Circadian rhythms coordinate physiology with the 24 h light‐dark cycle, and their disruption contributes to diseases spanning metabolic, cardiovascular, and neuropsychiatric domains. Whether the temporal coherence between wearable‐derived activity and temperature rhythms predicts long‐term health outcomes in free‐living humans remains unknown. Here, analyzing week‐long concurrent wrist‐worn acceleration and device temperature recordings from approximately 90,000 UK Biobank participants