The UTA gear lists look fairly good.
https://uta.knack.com/ultra-trail-austr ... eck-lists/Enough to insulate most runners from the cold if support arrives within an hour or two. And with marshalls spread a long the course its reasonable to presume support can be provided within that window as long as a injured immobile runners location is known.
I wonder what the required kit for the race in China was..
Edit. This is a fairly good summary of the race, equipment carried and discussion on what went wrong.
https://www.trailrunnermag.com/people/a ... ng-tragedyThe bigger challenge with trail running especially in alpine regions is normal training runs. Without the fast response from race support how is a runner going to protect themselves from hypothermia if they fall and can't move. The uta kit above won't cut it for more than a couple of hours in freezing wet conditions.
Of course same could be said of day walkers or hut to hut walkers who aren't carrying tents or a bivy.
And despite the perceived risk you don't thankfully hear of many incidents involving runners.