The 5 W's of post-operative fever

Wind---pneumonia, atelectasis at 1st 24- 48 hours
Water---urinary tract infection at Anytime after post op day 3
Wound---wound infections at Anytime after post op day 5
Wonderdrugs---especially anesthesia 
Walking---walking can help reduce deep vein thromboses and pulmonary embolus usually occures at Day 7-10