This study will use a traditional cluster randomized crossover design with patients in five medical intensive care units at the Cleveland Clinic to evaluate the efficacy of silk-like bed sheets and underpads for prevention of Unit-Acquired Pressure Ulcers (UAPU). Adult hospitalized patients in beds with standard bed linens versus those with silk-like linens will be compared for 1) rate of development of UAPU, 2) time to develop the first UAPU, and the maximum severity of any UAPU that develop. Bed linens will be changed per unit protocol. Patient characteristics will be summarized using frequencies and percentages for categorical factors and means, standard deviations, percentiles and median and range for continuous measures. For the primary outcome of unit-acquired pressure ulcer rate, generalized linear mixed models, assuming a Poisson distribution for the outcome, and unit length of stay as an offset will be used. For the time to event analysis, frailty models will be used to assess whether time to first pressure ulcer differs between treatment types. Generalized linear mixed models will be used for other secondary endpoints, including maximum severity of observed pressure ulcers