Mary told me about two of her daughter’s friends whose families had to move after the girls had recurrent high altitude pulmonary edema (HAPE). This is easy to recognize in it’s classic form: a tourist has trouble breathing during the first 48 hours at altitude. But these girls lived here, and got sick returning from visits to lower latitude, which we call “reentry” HAPE. Both forms are not common, probably less than one out of one thousand people are affected. Certain people are more susceptible. Luckily it is prevented by taking diamox (acetazolamide) before traveling.
For families who live here I recommend buying a home pulse oximeter for less than $50 at Walmart or Walgreens. The affect person can have oxygen ordered by their doctor and delivered to the home if readings are below 90% saturation. The good news is that it doesn’t happen every time they travel and they tend to outgrow reentry HAPE in the teen years.