Pediatric environmental-medicine specialist Dr. Catherine Karr has some practical ways for those who are pregnant to take extra precautions during wildfire season. She says to stay indoors and in clean air spaces during heavy smoke days whenever possible, and to avoid creating indoor pollutants by frying food or lighting candles. “We found that there was a higher risk of preterm birth with higher exposure to wildfire smoke,” said Dr. Karr. “Unfortunately, in the western United States, that's whe