While everyone has the same sensitivity to wildfire smoke. It's still a good idea to avoid breathing in smoke. And when smoke is heavy, such as can occur in close proximity to a wildfire, it's bad for everyone.
Smoke is made up of a complex mixture of gases and fine praticles produced when wood and other organic materials burn. The biggest health threat from smoke is from fine particles. These microscopic particles can penetrate deep into your lungs. They can cause a range of health problems, from burning eyes and a runny nose to aggravated chronic heart and lung diseases.
Exposure to particle pollution is even linked to premature death.