Update 7:10 p.m.
The hiker was in cardiac arrest when Cal Fire reached him, according to the Riverside County Sheriff's Department. The Riverside County Mountain Rescue unit was also called in to assist with the recovery of the hiker.
A hiker died on a trail in Idyllwild today despite efforts to resuscitate him, a fire department spokeswoman said.
Someone reported a hiker down on the Ernie Maxwell Trail at Humber Park at 10:50 a.m., Riverside County Fire Department spokeswoman Melody Hendrickson said.
"CPR was being performed on the adult male patient prior to firefighter arrival. Firefighters took over resuscitation efforts. However, the patient was pronounced dead at the scene," Hendrickson said.
The man's age and identity weren't immediately released, and the cause of his death was under investigation.