I bring baby Vicks, betadine, thermometer when we travel. I don't bring meds, because usually it will be over the counter in case I need it. I express milk and put them in bags 100ml max only to make sure I don't have problems if I will hand carry the milk. I also make sure to bring lots of ice pack. I leave everything with the hotel's freezer the minute we arrive. I also ask them to keep the milk in their freezer as well. I put it in a bag before I hand it over to them. I make sure all the milk are frozen for our trip home. If we have checked-in luggage, then I don't worry about my milk being over 100ml. I then pack everything in an insulated bag then put ice pack all around the milk.
My friends pack a simple first-aid kit which includes: - Thermometer - Antiseptic wipes - Gauze pads - Hand sanitizer - Disposable tweezers - Band-aids - Some medications and ointments for rashes and scratches