A mountain biker who stopped to help rescue 4 dehydrated hikers in the scorching San Diego desert died on his way back to his group

• A 24-year-old mountain biker in San Diego died after helping four hikers in the scorching desert heat.
• The cyclist, who was not named, and his friends had stopped to aid the dehydrated hikers on Saturday.

A 24-year-old mountain biker died on Saturday after helping to rescue four hikers who were dehydrated in the 106-degree San Diego desert heat, the authorities said.

The cyclist, who was not named, and his friends were in Jacumba when they came across four hikers who were suffering from heat exhaustion and dehydration, a fire official told NBC San Diego.

The hikers didn't have food or water, and emergency services received a call in the early afternoon saying the group was suffering from symptoms related to heat illness, per the outlet.

The mountain biker and another cyclist stayed with the four hikers, while two other cyclists went to a trailhead about five miles away to give directions to an arriving emergency crew, according to Fox 5 San Diego.

Paramedics evaluated the four hikers, who were treated and released at the scene, fire officials told Fox 5.

With the hikers rescued, the mountain biker and his friend, who both stayed behind, started riding down the trail to meet the other pair, Fox 5 reported.

The 24-year-old biker collapsed multiple times along the way, San Diego County Public Safety Group representative Chuck Westerheide told NBC San Diego.

At one point, he became separated from his friend, who was the only one to make it back, Cal Fire Capt. Brent Pascua told The San Diego Union-Tribune.

The other cyclists eventually found their unconscious friend about a quarter of a mile from the trailhead, Pascua said.

He was brought to an air-conditioned truck, then evacuated via an air ambulance, Pascua said. Paramedics worked to save the cyclist's life, but he was pronounced dead at 5:45 p.m., Pascua added.

The cause of death has not been determined, NBC San Diego reported.

Temperatures in Jacumba reached up to 106 degrees Fahrenheit on Saturday, according to AccuWeather.

In a Saturday Facebook post, Cal Fire wrote that it assessed six people onsite, and was treating one patient in critical condition.

"A huge thank you to the bystanders that were able to lead the firefighters and rescue helicopter in to where the patients were in this very rugged and remote area," Cal Fire added.

The department urged people to bring an "adequate amount of water and food" when out in the countryside, and to "plan activities earlier in the day when the temperatures are cooler."

"When it's this hot, maybe it's a good idea to plan the hike another day, or at least really early in the morning so it's not in the heat of the day," Pascua told NBC San Diego. "And when you do, take lots of water, take extra water than you think you're gonna need."