You can know and trust your equipment as well as possible, but there are limits to human endurance and capabilities.  Kate activated a GPS tracker beacon when she got into trouble, but it’s not a sure thing.   In this kind of weather, maybe bring a buddy.  When it’s 30 below out, maybe stay indoors.

“Unfortunately, a lot of the coordinates that we received over the night are all over the place within a mile circumference,” said Lt. Jim Goss of New Hampshire Fish and Game.
Crews were forced to suspend the search because of the extreme conditions.
“Well, I think the temperature last night was 30 below, and there were winds of over 100 mph on the summit,” Goss said.

RIP Kate.

(pictures from other sites)

http://www.wmur.com/news/rescuers-search-for-missing-hiker-near-mt-adams/31294362