A 35-year-old woman is admitted to the burn unit on day 3 post-injury with a 40% TBSA deep partial-thickness burn to her trunk and lower limbs. She is on Parkland resuscitation with adequate urine output. On examination, the burned areas are dark brown, leathery, and painless. There is a clear demarcation between burned and unburned skin. Her vital signs are stable, and she is afebrile. What is the most appropriate next step in management?