I am an emergency physician in Pennsylvania and noticed one of our nurses wearing one of your vests. She loves it and i deeply respect her opinion. Therefore, I decided to purchase multiple vests for nursing partners, my wife, my daughter, my mother-in-law, and my mother. Essentially everyone female in my life. Delaney is nine years old and wears a size small. She wears it every day to school and it keeps her warm in the chilly classrooms. If she keeps it on white it lasts all day with red reserved for recess and the trip to and from school. Everyone, I’ve given this vest to had rave reviews of the warmth, ease of use and comfort. The only suggestion would be to buy a second battery. Two thumbs up from Lancaster Pennsylvania !!!!