For me, the trickiest part to having a type 1 diabetic at Summer camp is overnight. The activity level at camp is so much higher than at home plus there's different food, snacks all the time, and the excitement of being around friends all day/night. During the day, the fluctuations are relatively easy to manage but at night they'd end up bottoming out.
The first year we had a camper with diabetes, the overnight on call nurse was in her cabin 3-5 times a night for the first week and the camper was almost sent home. In the end, her endo adjusted her basal rates and we would send her to be running a little high (180-200) and that helped.