![Wildfire smoke A large branch of a tree burns during a wildfire](https://toolkit.climate.gov/sites/default/files/styles/splash_image/public/fire-1519428.jpeg?itok=X2UavqoG)
Planning Framework for Protecting Commercial Building Occupants from Smoke During Wildfire Events
Wildfire smoke is composed of fine particulate matter and gases. Although wildfire smoke contains multiple contaminants, this document focuses on controlling exposure to particles less than 2.5 microns in diameter. Breathing high concentrations of these pollutants has many potential acute and chronic health consequences, including reduced lung function, pulmonary function, bronchitis, exacerbation of asthma and other lung diseases, exacerbation of cardiovascular diseases, such as heart failure, and even premature death. While most healthy people will recover quickly from exposure to smoke during a wildfire episode, some susceptible populations are at greater risk of health effects, including people with existing health conditions, particularly of the heart or lungs. This planning framework provides guidance on reducing exposure to and minimizing impacts from this harmful particulate matter created by wildfire and prescribed burn events.