Shortly after, firefighters were called to Pima Canyon Trail on South Mountain after a 43-year-old woman said she was out of water and experiencing vertigo on a trail.
Rescue crews used an IV to treat the woman and she was able to walk down the mountain with assistance, a fire spokesman said. The woman did not need to be hospitalized.
At 9:45 a.m., firefighters responded to a mountain trail at 51st Avenue, north of Happy Valley Road, where two adults reported feeling overheated and distressed.
Officials say the two people were able to walk down the trail and not did need assistance after resting and dehydrating.
About an hour later, Phoenix firefighters received reports of a fourth incident at a mountain near North Valley Parkway and Dove Valley Road.
A fire spokesman says a 14-year-old girl was hiking with her parents when she began suffering heat-related symptoms.
The teen was helped down the mountain using a four-wheel drive vehicle, officials said. She was treated at the scene and did not need to be taken to the hospital afterward.
No rescuers were injured during the incidents in Phoenix, fire spokesman confirmed.
A fifth incident was reported on the Sunrise Trailhead in north Scottsdale where an injured hiker was helped off a mountain by helicopter, authorities said. The hiker is in stable condition and no additional information was released.
Later in the afternoon, fire personnel responded to the southwest portion of South Mountain for a lost hiker who was out of water and reported feeling weak. According to a fire spokesman, a Firebird rescue helicopter was called in to assist and locate the man. After the man was located, he reportedly had severe cramping and was showing signs of dehydration. He was taken to the hospital for further evaluation.
As of July 1, the Phoenix Fire Department had already responded to 125 mountain rescues.
An Excessive Heat Warning is in effect Monday through Wednesday. As a reminder, it's best to stay indoors as much as possible and keep yourself hydrated.