Under those conditions getting a fire going might well be somewhere between extremely difficult and impossible.
Also: note the age group. Only one of them was under 50. OAP's playing spring chicken.
Like it or not: the older you are, the less you are able to withstand. And yes, ladies and gentlemen, there are exceptions to that.
A simple shelter tarp like a lightweight poncho and a few feet of line, for an improvised shelter, would probably have saved them.
Waterproofs, extra clothing and chemical heater packs like the commonly sold handwarmers are lifesavers.
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I don't do dumb & helpless.