What precautions are advised for a family travelling with a 4 yr old baby?

When the parents are with the baby then I guess they know to take all the precautions like: not to leave the baby alone; make sure that she doesn't eat something wrong or something that has choking hazard; to never leave the baby unattended etc. These were the precautions that all parents or elders who accompany kids would know but I can make a suggestion that we generally forget the following things when travelling with the kids that we must not. So the things that we should do while travelling are to always carry basic medicines for cold, cough, tummy ache and ear ache and fever. Take her toys or dolls or whatever thing is her favourite to keep her engaged.