Spring and summer in the U.S. now come with a new normal: days and even weeks where the acrid overhang of wildfire smoke forces us indoors. At its worst, not even shuttered windows can protect us from its effects—the stinging eyes, runny noses and burning lungs.

Many of the near-term problems with wildfire smoke exposure are now well understood.

The most serious, of course, is death. A recent working paper for the National Bureau of Economic Research estimated that the U.S. would see nearly 28,000 more deaths each year by 2050 due to the climate-driven rise in wildfire smoke—that’s 76% higher than the average annual deaths between 2011 and 2020.

More people experience milder but still serious consequences, like worsening asthma and debilitating headaches. When smoke from Canadian wildfires wafted thousands of miles to hang over large tracts of the U.S. last summer, it led to a 17% rise in asthma-related ER visits, according to the Centers for Disease Control and Prevention.

More recently, less-obvious health issues have come to light. Multiple studies have found a connection between wildfire smoke and pregnancy complications, including preeclampsia (a form of dangerously high blood pressure) and premature births.