Two additional links with a few more details:

http://bc.ctvnews.ca/hikers-survive-week-in-b-c-wilderness-with-2-oranges-3-cookies-1.2445693

http://www.pentictonwesternnews.com/news/311060821.html?mobile=true

@clearwater: I agree that people who are regularly exposed to high temperatures become acclimatized and can function. The same is true of cold temps. It's a process that takes time. I have a terrible time with high temps; it took me two weeks to start to acclimatize to Hawaii in the summer, while all around me were Californians thankful to escape the heat.

My guess is that the search was called off because the searchers couldn't find the slightest indication of the hikers, who had apparently hunkered down in a place that was hidden from aerial view, possibly outside of the defined search area. Dogs and ground searchers couldn't find a trace either.