The first 72 hours after a burn injury occurs are the most critical. In the first 72 hours, patients will lose fluids, resulting in blisters, swelling, and low blood pressure. Physicians and nurses must help prevent the fluid loss and controlling infection. Massive amounts of intravenous replacement fluids may be necessary in large body surface area burns. When the patient is stabilized, the staff will begin cleaning the wounds to prepare them for treatment.