PHOENIX (AZFamily) — Extreme heat is bringing trail closures to Phoenix, but fire responders say some hikers are not following the rules, putting rescuers at risk when emergency calls come in. Under the Phoenix Trail Heat Safety Program, restrictions and closures take effect during extreme heat. Certain popular hiking trails, including Camelback Mountain, Piestewa Peak and parts of South Mountain, are closed from 8 a.m. to 5 p.m. during extreme heat warnings to protect hikers and first responders.