Three large wildfires burning across multiple Southern California counties have led to poor air quality, with a smoke warning in effect, with a warning for possible “hazardous” respiratory problems issued Wednesday.

All in all, the Fire at airport, Line fire And Bridge fire tore through more than 100,000 acres Wednesday morning, leaving thousands facing mandatory evacuation orders and forced to flee their homes as weather conditions continued to complicate efforts to battle the blazes. A smoke warning related to the wildfires has been extended, according to the South Coast Air Quality Management District.

The measure will remain in effect until 11 p.m. on Thursday.

This latest smoke warning is especially notable because air quality regulators warn that the smoke from the wildfires could create conditions so damaging that they would be classified as “hazardous.” That’s the worst possible air quality, according to the categories listed on the Environmental Protection Agency’s AirNow.gov website.

EPA officials say everyone in this category is more likely to be affected.

Less harmful air quality, under the “unhealthy for sensitive groups” category, is also expected in some areas of Southern California. This indicates that the general public is less likely to be affected, while people with chronic health conditions or others who are more sensitive to air pollution, such as those with asthma, may experience harmful side effects.

The bad conditions are expected in parts of Riverside, Orange, San Bernardino and Los Angeles Counties. The LA County coastline will see the least severe impacts, according to air quality officials.

Here you will find a searchable map with current weather conditions.

Tips to stay safe

Given the current circumstances, the South Coast Air Quality Management District is warning people in affected areas to take certain steps to protect their lungs. The agency has provided the following list of tips.

• Try to stay indoors and keep windows and doors closed
• Turn on an air conditioner or air purifier
• Avoid burning candles or incense
• Try not to do any strenuous physical activity or exercise when you are outdoors
• Avoid activities such as baking and grilling
• Wear an N95 or P100 respirator when outdoors to ensure protection