An extreme heat warning is in effect for the Grand Canyon in areas below 4,000 feet in elevation. For example, on the south rim, highs will range in the mid-to-low 80s, but down at Phantom Ranch, it will be above 110. See a spelling or grammatical error in our story? Please click here to report it.

Heat cramps are painful muscle cramps and spasms, usually in the legs and abdomen. They may also be a symptom of heat exhaustion. Apply firm pressure on cramping muscles or gently massage to relieve spasms. Give sips of water unless the person complains of nausea, then stop giving water.

Temperatures across the UK are expected to rise this week, with the fourth heatwave of the summer on its way for some parts. Amber and yellow heat health alerts have been issued in England, from 12:00 BST on Monday until 18:00 on Wednesday by the UK Health Security Agency (UKHSA ) and the Met Office.

An Extreme Heat Warning remains in effect for central and southwestern Arizona through 8 p.m. Tuesday. For the Grand Canyon below 4,000 feet, the warning remains in effect through Thursday night. A new Extreme Heat Warning is also in effect for northwestern Arizona on Monday and Tuesday.