Two men were treated by first responders this morning after feeling ill while hiking the Koko Head Trail in Hawaii Kai, Honolulu firefighters said.

At about 7:40 a.m., firefighters first received a call about an 18-year-old man who had fallen down while hiking, said Honolulu Fire Department Capt. Scot Seguirant.

Firefighters found the 18-year-old man had fallen while on the trail, possibly from a medical condition, and placed him on a backboard for stability before flying him off the mountain with a helicopter, Seguirant said.

He was taken to Koko Head District Park and transferred to Emergency Medical Services personnel.

An EMS report said medics treated the hiker and took him to a hospital in serious condition.

While responding to the injured hiker, firefighters also assisted a 44-year-old man who was feeling ill on the trail. Firefighters walked him off the trail and handing him over to paramedics.

EMS said the older man was also treated at the scene, but he refused to be taken to a hospital.