The provisions of this chapter shall not apply when any one (1) of the following conditions exists:
(1) The motor vehicle is being used as an ambulance or other emergency vehicle;
(2) When an emergency exists that threatens:
(A) The life of any person operating a motor vehicle to whom this section otherwise would apply; or
(B) The life of any child who otherwise would be required to be restrained under this chapter; or
(3) If any child who would otherwise be required to be restrained under this chapter is physically unable because of medical reasons to use a child passenger safety seat system or seat safety belt and the medical reasons are certified by a physician who states the nature of the medical conditions as well as the reason the use of a child passenger safety seat system or seat safety belt is inappropriate.