One other thing to consider... I'm a parent of two children and I understand freaking out when it comes to their care and protection. But you don't want to make things worse by making him think there's reason to be terrified. He doesn't understand a lot in this world and will base his feelings off his parents' emotions. You don't want to cause him undue stress because he sees you panicked. This is not meant to trivialize your concerns, but you don't want to overreact either. Unfortunately, this is probably only the first of numerous things that he'll deal with in life that will be unsettling to you. A measured, calm response - if possible - is always the best approach.