Who takes care of my children if they would ever need critical care treatment?

Specialists: Although the age definition of "children" may vary, i will assume you ask about younger children (not late teens). In that case, a specialty team led by pediatric intensivists would provide this care. Other pediatric specialists, picu nurses and respiratory therapists as well as other support teams will care for your child. These groups are highly trained and are dedicated to the critically ill.

Critical care doc: If your child needs critical care treatment, he/she would presumably be cared for in an intensive care unit (icu), or more specifically a pediatric ICU (picu). The main physicians caring for your child there would be pediatric intensivists and/or surgical critical care specialists. There might be other specialists consulting on the case, too. There would also be ICU nurses and other therapists.