or a medical condition which means that they need to be kept near a vehicle at all times either for treatment or for transportation to a location where treatment can be performed.
neu cyflwr meddygol sy'n golygu bod angen i'r plentyn fod yn ymyl ei gerbyd modur bob amser naill ai i gael triniaeth neu i'w gludo i leoliad lle gall gael triniaeth.