PORTLAND, Ore. (KOIN) — Health officials in Multnomah County announced a restriction on voluntary burning Friday because of the wildfire smoke and forecasted stagnant air conditions.

The wood burning advisory is in effect beginning at noon Friday and will be lifted when conditions improve.

During the advisory, county residents not using wood as a heat source should avoid using fireplaces, wood and pellet stoves, as well as burning outdoors.

For those that must use wood as a heat source, officials suggest burning dry, seasoned wood that is split and covered, testing wood for 20% moisture or less, using an EPA or DEQ-certified gas or wood stove and burning small but hot fires. Officials remind residents to never let a fire smolder.

This announcement comes a week after Multnomah County ended its outdoor burn ban.

Fire officials said that the restriction was lifted due to cooler temperatures, an increase in nighttime moisture, and the return of rain showers contributed to officials’ decision to lift the ban.