The city of Phoenix is restricting some of its most popular hiking trails due to an Extreme Heat Warning from the National Weather Service. This comes as the city is expected to face at least four more heat warnings in the coming days. The earliest Extreme Heat Warnings were issued in the year, back in 2020. Wednesday marked the first day in 2026 that Phoenix reached triple digits. Despite the restrictions, some hikers have mixed feelings about the restrictions. Phoenix Fire Captain Todd Keller urged hikers to hydrate well the night before hiking on an open trail and try to hit the trails on a cooler part of the day. The city's Parks and Recreation board has started the Trail Heat Safety Program in 2021.