Going barefoot in the desert is never really a good idea

Even when I wore beachwalkers (thongs) which are a type of sandal often I would step on a Cholla Cactus that had fallen off the bush in the desert and cholla barbs don't easily come out of your flesh or at all. I still have pieces of cholla cactus likely in my feet and legs from when my parents and I built a retirement home for them from 1968 to 1980 when my father retired there near Yucca Valley, California.

Also, when it is 120 degrees out the ground is 120 degrees out too especially the pavement that your car drives on but also the sand or dirt or rocks you might walk on. So, at 120 degrees out you are at the very least going to burn your feet pretty bad going barefoot anywhere to the point where you could wind up in the hospital.

Even walking anywhere in 120 degrees (more than a block or so) can be fatal for many people around the world. Though you can survive it this hot for awhile if it is dry enough like it gets in Death Valley or Las Vegas or Palm Springs or Phoenix, Arizona, 120 is often fatal for people not familiar with what their body is going to do in that much heat if they have never experienced it before. It sounds like the guy from Belgium had never been anywhere this hot ever before which made him the perfect victim in this situation. 

Just remember if it is too hot to think straight then you can't make the decisions you need to to stay alive. So, if someone doesn't rescue you in time then you are dead and gone.