Walking in the hot sun of New Mexico and ignoring the warnings and advice posted on the trail, in both French and English. Their nine year old son survived.
http://www.foxnews.com/us/2015/08/10/french-couple-dead-after-hike-in-new-mexico-child-rescued/?intcmp=hplnws
http://www.foxnews.com/us/2015/08/10/french-couple-dead-after-hike-in-new-mexico-child-rescued/?intcmp=hplnws