In 2021, fires killed 4,316 Americans, and over the past 10 years, fire deaths have increased by almost 18%. Most die not from burns but from oxygen deprivation caused by smoke inhalation. Immediate survivors of the blaze are not out of the woods. The consequences of smoke inhalation can show up hours or even days later. Healthy people can die even when they seem able to breathe. When treating smoke inhalation, here’s what not to do—and what you must do instead.