A 10 year old boy was wheeled off Camelback Mountain Saturday morning after overheating. The trail he was on was closed at the time. Phoenix Fire got the call around 11 a.m. for a hiker in a medical emergency at the Echo Canyon Trailhead. Crews found the boy, who had been hiking with his parents and was suffering heat-related illness. They brought him down on a big wheel, a stretcher with a single wheel underneath built for terrain an ambulance gurney can’t handle, and he was taken to a hospital in stable condition. Here’s the part worth knowing if you don’t hike much. Phoenix closes Echo Canyon and the Piestewa Peak summit trail during extreme heat warnings, and Saturday was one of those days with the Valley pushing 116. FOX 10 reported the trail was closed when the call came in and that it’s unclear why the group was on it. Capt. Todd Keller with Phoenix Fire gave the simplest version of the rule anyone’s put out this summer. When you’re halfway through your water, you’re halfway ...