This storyoriginally appeared on Gristand is part of theClimate Deskcollaboration. On a hot summer day in New York City last July, Ajohntae Dixon was studying at home when he began struggling to breathe. With no air conditioning in his apartment, the temperature inside surged, and the 15-year-old’s gasping quickly progressed into a full-blown asthma attack under the oppressive heat. He took his inhaler and then tried his nebulizer, but he was still fighting for air.