text:  400 to 600 people a year going to emergency room visits for heat. That's a significant number of people. Felton suspects those numbers may underestimate the true impact of heat in Hawaii. People may show up in the emergency department with a heart problem. Maybe they had a pre-existing heart condition, and it may be heat that triggers that heart attack or that heart failure. But it may not be included as part of the diagnosis that we can data mine.