This is making the news today due to the lawsuit, the death happened during the hottest part of the summer, the end of June, 2017. I lived in the Davis Mountains as a child and know the difficulties of doing anything there: oxygen is scarce! This was an unnecessary death, one has to be ‘hardened’ by heat and low oxygen before strenuous hiking/climbing in hot mountains. I spent most of my childhood hiking, running, climbing mountains in the Southwest. And Texas is very humid compared to say, Arizona! Humidity makes heatstroke even more likely!