Jerry, a Maine resident, has a chronic respiratory infection. His doctor recommends that he spend a few weeks in a special ecological environment facility where the air is especially purified. Jerry flies to New Mexico for three weeks. While in New Mexico he sees a doctor twice for checkups. His expenses are as follows: $500 for the plane ticket, $1,500 for lodging, $800 for meals, and $200 for doctor's fees. Which of these expenses, if any, qualify as medical expenses under §213?