An alert is in effect Friday that warns people to be wary of the poor air quality in Fresno, the San Joaquin Valley Air Pollution Control District said.

The warning previously only affected people with lung ailments like asthma, but that changed Friday to include all people in the Fresno area.

There have been reports of some teachers canceling classes due to the poor air quality and visible smoke, and many students have complained of headaches and other allergy issues.

The cause of the unusually smoky air is a wildfire burning roughly 50 miles from Fresno State.

“There is a high pressure system over the West Coast,” said Carlos Molina, meteorologist with the National Weather Service in Hanford. Molina said that the air that normally flows west to east is now being pushed westward into the Valley.

The Rough fire, which was started by a lighting strike on July 31, has scorched more than 110,000 acres across California and is only 29 percent contained.

More than 2,100 firefighters are working tirelessly to extinguish the blaze, but it continues to grow. The Rough fire is the largest wildfire in California.

The combination of the particulates in the air from the fire and the high temperature has created a mix that is unhealthy.

The high temperature for Friday will be 105 degrees.

Fire officials said evacuation warning notices continue to be in place for people living in the communities of Pinehurst, Miramonte and Dunlap.

Locally, the air quality alert is in effect until at least midnight Saturday morning.