Last winter we went on our first family ski vacation, and as the kids and I were learning to ski, we noticed that Annie's numbers were very high. I thought perhaps it was the cold weather, and kept preparing myself for dramatic lows once she warmed up and the effects of all the exercise kicked in. That never happened, and I found myself giving her more and more insulin to try and get the numbers down.

When we returned home and life was back to normal, I asked Dr. Cogen why Annie had been so...