These data describe were derived from a study that evaluated the use of wearable sensors for monitoring the real-time health of individuals wearing PPE to mitigate risk of developing an HRI and enable timely intervention. This dataset is associated with the following publication: Hegarty-Craver, M., D. Womack, J. Thornburg, T. Boe, M.J. Archer, and W. Calfee. Predicting Risk of Heat-Related Injuries for Individuals Wearing Personal Protective Equipment Using Smartwatches: Feasibility Observational Study. JMIR Formative Research. JMIR Publications, Toronto, CANADA, 9: e72324, (2025).