Guillaume Federighi, aka Hey Gee, is a French and American author and illustrator. He began his career in 1998 in Paris, France. He also spent a few decades exploring the world of street art and graffiti in different European capitals. After moving to New York in 2008, he worked with many companies and brands, developing a reputation in graphic design and illustration for his distinctive style of translating complex ideas into simple and timeless visual stories. He is also the owner and creative director of Hey Gee Studio, a full-service creative agency based in New York City.

Charles is a high-energy 7 year old with asthma. Born prematurely, his family has helped him manage his chronic lung disease throughout his life. He now uses an inhaler daily, and a nebulizer when he gets sick, to help him keep up with his active life.

Manuel Arteta, M.D., is a pediatric pulmonologist at Mayo Clinic Children's Center in Rochester, Minnesota, with special interests in severe asthma in children and childhood interstitial lung diseases.