A 1 week old male born at full term presents to the ED with difficulty breathing and a weak cry. Mom also notes that he appears “sweaty” during feeds today and has had fewer wet diapers. History is significant for scant prenatal care however delivery was uncomplicated. On exam he is cyanotic with oxygen saturation 70% on 5L NC O2. Vital signs are as follows: T 36C, HR 180, RR 65, BP 60/30. Which should you order first?