You are called to a farmhouse on a sunny spring afternoon. Upon arrival, a frantic mother tell you that her 4-year-old daughter was playing in the yard, stung repeatedly by several bees. The patient is alert, screaming and crying, and can follow her mother’s commands. Her arms and legs are swollen and show the marks of several stings. Her body is covered in hives. Her vital signs are blood pressure 90/40, pulse 110, respiratory rate 24, and oxygen saturation 99 percent. Her lungs sounds are clear and equal bilaterally. You decide to administer oxygen. What is the best method?