Two Washington counties are implementing outdoor mask mandates beginning Tuesday, forcing individuals attending large outdoor events to mask up and recommending them to do so in any outdoor situation where they cannot keep a six-foot distance.

The orders cover large events in both King and Pierce counties. Under the rules, those five and older must wear a mask outdoors if they are attending a large gathering, which is described as any event with over 500 people.

King County health officer Dr. Jeff Dunchin cited the “surge in delta cases and serious impacts” on the healthcare system, prompting him to promote “multiple, layered protection steps.”‘

“Most importantly, if you’re 12 years or older, get vaccinated. Wear a well-made and snug-fitting face mask any time you’re in indoor public spaces and crowded outdoor spaces, whether you’re vaccinated or not,” he said.

The order reads:

Masks are required at any outdoor event with 500 or more people in attendance. This requirement applies to all people, both vaccinated and unvaccinated, 5-years of age and older.

Further, in any other outdoor situations where people cannot remain at least 6 feet apart from nonhousehold members, use of face masks is strongly recommended for all people, both vaccinated and unvaccinated, 5-years of age and older.

The order also includes requirements for indoor masking, forcing everyone five and older in King County to wear a face covering in public indoor spaces. However, there has been a statewide mask mandate in place since August 23.

“We will continue to adapt our response measures to the reality of the evolving COVID-19 outbreak,” Duchin said.

“The Delta variant is more contagious through the air, causes more severe illness in adults, and we have a high level of community transmission in King County and Washington state,” he continued.

“Outdoors is much safer than indoors, but there is risk even outdoors currently when large numbers of people are in close, prolonged contact,” he added.

Pierce County’s order is virtually identical. It reads:

Face coverings are required at any outdoor event with 500 or more people in attendance. This requirement applies to all people, both vaccinated and unvaccinated, 5-years of age and older.

Further, in any other outdoor situations where people cannot remain at least 6 feet apart from non- household members, use of face coverings is strongly recommended for all people, both vaccinated and unvaccinated, 5-years of age and older.

“We are taking this step to ensure the most vulnerable people in our community do not become infected or spread COVID-19,” Dr. Anthony L-T Chen, director of health at the Tacoma-Pierce County Health Department, said.

“The highly contagious Delta variant is causing a rapid increase of positive COVID-19 cases and leading to increased hospitalizations and deaths,” he continued.

“Wearing masks in crowds of 500 or more will reduce community transmission and protect children under the age of 12, people who are immunocompromised and unvaccinated adults,” he added.

The news comes as the U.S. sees coronavirus cases rising over 300 percent from last Labor Day, despite the prevalence of vaccines and the prolonged use of masks.