Phoenix Fire Department crews rescued a 50-year-old woman suffering from heat exhaustion Monday after hiking at Camelback Mountain. The hiker became weak when descending the mountain near the Echo Canyon trailhead, Fire Department officials said. Crew used a "big wheel," essentially a tire attached to the bottom of a stretcher, to get the woman down the mountain. She was treated with IV fluids and hospitalized in stable condition following the rescue. The hiker had no other injuries and no firefighters were hurt.