Project Summary/Abstract The proposal aims to develop, validate and test a standardized tool that intended to assess latent risks in the physical healthcare environment. The Hazard Assessment and Remediation Tool (HART) will be developed in three parts. First, the proposal will establish an intra-class correlation coefficient (0.9) for expert raters applying the HART tool to simulated resuscitations. Frame of reference training will be used to assess inter-rater reliability of the tool using a separate team of raters. Second, the HART tool will be used to assess the tool's ability to discriminate between clinical environments with various physical attributes (e.g. comparing minimum required room size against twenty percent larger rooms) during critical clinical interventions. Additionally, analyses will be conducted to evaluate the correlation between HART score and completion of key clinical performance metrics (e.g. adherence to CPR guideline of chest compressor rotations every two minutes). Lastly, the proposal aims to develop and test a methodology to aid in the remediation of hazards in the clinical environment. Baseline measurements from the HART tool, in conjunction with staff surveys post-simulation, will be used to identify improvements in the trauma resuscitation environment. The HART tool will be applied to the improved environment to determine if changes produce a more favorable HART score. Secondary outcomes to the second and third aims of the proposal include team communication and coordination as well as physician and nurse workload. Although pre- construction simulation is growing in popularity, to date no standardized, quantitative, validated tools are available to identify latent hazards in clinical environments and systems. We propose to develop and validate a robust, quantitative tool that can be applied to clinical spaces under design or to existing spaces to assess and remediate physical hazards.