Hot as hades

Not a good hiking day up in the mountains:

MOSTLY SUNNY IN THE MORNING. PARTLY CLOUDY IN THE
AFTERNOON WITH A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS
THE SAN GABRIELS. AREAS OF SMOKE. HIGHS FROM 93 TO 103 AT LOW ELEVATIONS
TO THE MID 80S TO AROUND 90 AT HIGHER ELEVATIONS. AREAS OF SOUTH TO
NORTHWEST WINDS 15 TO 25 MPH.

The best local place I have found in these types of conditions is Icehouse Canyon on Mt. Baldy. The lower half is shady and besides a cold river (as the name indicates), and once you reach the upper half you can feel cool high altitude breezes. I went up there last summer when it was 100 degrees in Claremont, and felt pretty cool the whole way up to Timber Mountain.