100 attendees treated for heat-related illness at Colorado air show: Officials

At least 10 people were hospitalized and 100 others were treated for heat-related illness at a sold-out airshow in Colorado on Saturday, according to officials.

With 30,000 people expected to attend, the two-day Pikes Peak Air Show kicked off at the Colorado Springs Airport, about 90 miles outside of Denver.

A few hours after the event began, the Colorado Springs Fire Department said it was "actively responding" to a mass casualty incident.

At least 100 people were treated by emergency personnel onsite and 10 were transported to local hospitals, CSFD said in a statement.

An update on the patients was not given Saturday evening.

"We can call a mass casualty incident when we have something like this where we have multiple heat-related illnesses. That allows us to order more resources," CSFD Public Information Officer Ashley Franco told ABC affiliate, KRDO.

Temperatures reached a high of 96 degrees in the area, with little to no clouds in the sky, according to the National Weather Service.

"The Colorado Springs Fire Department works and prepares very closely with the airport and event organizers when large events are held. Today, like every day, we had a plan in place in the event we needed to activate it," said CSFD Chief Randy Royal.

The Pikes Peak Air Show is scheduled to continue on Sunday, with a heat advisory remaining in effect and a high of 93 degrees. CSFD advised attendees to come prepared, "With water bottles, hats, sunscreen, umbrellas and other essentials to combat the heat."

ABC News' Erica B. Morris contributed to this report.