This study investigated the biomechanics of simulated sideways falls from various bed heights onto two types of protective floor mats. This article presents biomechanical injury criteria for evaluating the probability of sustaining injuries to the head, thorax, and pelvis. A side-impact dummy was raised to drop heights of 45.7 cm, 61.0 cm, and 76.2 cm and released. Two types of protective floor mats were evaluated and compared with impacts experienced on an unpadded, rigid floor. Results of the study demonstrated a high risk (>50%) for serious head injury for falls onto an unpadded, rigid floor at 61.0-cm and 76.2-cm drop heights. Falls onto floor mats demonstrated significant reductions in injury risk to the head and pelvis for all drop heights. Thoracic injury risk was significantly reduced for all but the highest drop height.