An emergency backpack for a child should contain an information card with their name, contact details, and medical information; a complete change of clothing appropriate for different weather; toiletries like toilet paper or wipes and diapers if needed; any necessary medication for 24 hours though cookies are not considered medication; a comforting letter and family photo from parents; and a non-perishable snack like granola bars though pasta is impractical, and the backpack should be light enough for the child to carry with their name and class on the outside.