Forecasters say lower elevations in northern Arizona will see potentially dangerous heat this weekend.
The National Weather Service put an extreme heat warning in effect from Saturday at 10 a.m. through 7 p.m. on Sunday for areas in the Grand Canyon below 4,000 feet.
Temperatures at Havasupai Gardens could hit 102 degrees and highs at Phantom Ranch will reach 110 degrees.
Officials warn hikers on the Bright Angel Trail not to descend below 1.5 miles from the upper trailhead and to avoid physical activity between 10 a.m. and 4 p.m.
Hikers should also have salty snacks, sufficient water and electrolyte mix and also double calorie intake to maintain energy and avoid heat-related illness.
For more info, see the Grand Canyon National Park's key hiking messages page.
The extreme heat warning also applies to Supai Village on the Havasupai reservation.
NWS has also issued extreme heat warnings for most of southern Arizona where Tucson's high is set to reach 111 degrees Sunday with 112 degrees in Phoenix.