ANO “Children’s Camp FOX CAMP (Lager’ Lisonok)” has been operating in Russia since 2019. Changes of observations in the Moscow region, Sochi, Kaliningrad region, Sochi, Gelendzhik, Chelyabinsk region, Altai. In the period from 2019 to 2022, 796 children and adolescents with type 1 diabetes mellitus (DM1) visited the shifts and active tours of the ANO “Children’s Camp FOKS CAMP (Lager’ Lisonok)”. The priority of children’s recreation is a focus on increased activity: marathons at various distances, football matches, basketball, alpine skiing and long hikes in the mountains, rafting. It is known that activity in patients with type 1 diabetes increases sharply by the level of blood increase, by a decrease in this indicator. In order, to prevent the development of hypoglycemia during heavy exercise, it is very important to quickly determine blood glucose using a glucometer and take the necessary measures to stop it. Thus, the presence of sufficient shifts is necessary to quickly and accurately carry out self-monitoring, sometimes in various and difficult conditions (on mountain trails, on a suspension bridge, when rafting on a mountain river, on the beach). This article presents the development of events on elevated blood levels in children and adolescents with DM1 in the conditions of the marathon, running at various distances in the conditions of the summer shift in the Moscow region of the children’s health camp ANO “Children’s Camp FOX CAMP (Lager’ Lisonok)”.