I also thought of Lucas.
Additionally, this case reminds me of the disappearance of Sam Dubal, of Berkeley, a PhD professor and Stanford/Harvard alum, who vanished while backpacking on Mt Rainier. He was described as an avid hiker who had experience trekking in the Himalayas.
When Sam went missing there were snow storms forecasted in the area he was hiking in. The temperature was in the triple digits in Pleasanton when Philip set out for his run.
As a frequent hiker and traveler (often in canyon county that's over 100 degrees with little shade - with lots of skin coverage, ample extra water, frequent breaks, wet bandanas, slow movement ect), I highly suspect this has to do with preparations for the weather, but I also share your sentiment in hoping that this case has a better outcome than Lucas' or Sam's
IMO