Drought and extreme heat, both exacerbated by climate change, have paved the way for prime fire conditions across the Western United States. As wildfire season ramps up and smoke re-emerges as a serious health threat, experts are encouraging people to get smoke ready. This includes stocking up on air purifiers and filters and, for those with lung disease at highest risk, refilling medical devices like inhalers.

But what if the very devices used to treat the health effects of climate change are themselves contributing to the crisis?

Such is the case with metered-dose inhalers, which are prescribed to treat two of the most common respiratory diseases in the United States: asthma and chronic obstructive pulmonary disease. These inhalers use hydrofluorocarbon aerosol propellants to help deliver medication into the lungs. The propellants are greenhouse gases that can trap heat roughly 1,500 to 3,600 times as well as carbon dioxide over 100 years.