We were somewhere over the Atlantic, on the long haul back from Johannesburg after a field visit in Southern Africa. Next to me sat our nutritionist, a wonderfully spontaneous colleague whose energy had kept us alive through long, hot days in the field. I was hoping for a quiet flight — maybe even some sleep. Then the inevitable announcement rang out:“Is there a doctor on board? Could he or she please make themselves known?” Before I could react, my colleague shot her hand into the air with all her usual enthusiasm. My usual excuse — “Let’s wait, there are surely better doctors, you’re only a pediatrician” — didn’t fly anymore.…