It is evident that things didn't go well at the ravine
Yes, and the question is 'why?'. The bonfire at the Cedar tree should provide warmth, but two Yuras managed to freeze to death near its flame. The ravine should provide safe shelter, however 4 hikers found their death there. Zina, when staring back to the tent, obviously expected to walk all way up and then return to the Cedar tree with so badly needed clothes and equipment, but she was able to cover just half way up. Rustem and Igor managed even shorter distance. Why did not experienced and strong hikers resist frost and wind much longer?
The fire at the cedar was not adequate to warm the hikers against the cold and we don't know if it was a last attempt for survival or to warm the two Yuri's alone or the whole group . To make a den flooring and a fire with flooring 70 meters apart suggests the two locations had different priorities or their initial plan changed . It would make more sense if the den flooring was found next to a fire.
My thoughts have changed endlessly about possible scenarios but I work a model from the basis of a wind slab, snow collapse , animal , wind or some other natural force of nature that made them leave the tent . So this has some connection to my thought process and is not meant to dismiss other people's ideas and I try to take baby steps where I can with as little leaps of faith as I can.
From the moment the hikers leave the tent , the clock of hypothermia starts ticking , this will have a host of variables, how warm they were initially in the tent , the energy they used to get over the pass ,erect the tent platform and if they were already damp from those activities for example . We don't know the wind chill, humidity, temperature, visibility or time of day but we know the biggest danger is the cold and it was cold .
Ultimately the hikers died of hypothermia which is when the body core temperature drops to a point where it can't heat itself. They also suffered varying levels of frostbite which is the start of freezing to the body but not the cause of death.
So as for the 'why ?' To your question , they were exposed to the elements, as time passes the body starts to shut down , including the brain , hands and joints start to stiffen up , feeling and touch are lost .
Some potential scenarios are that they fell in to the ravine and some hikers got partially wet , this would greatly amplify the seriousness of the situation and may explain an effort to try and dry some clothing that was found with burns in and around the fire and on the hikers. People with cold and frostbite will stick their limbs into a fire as there can be no feeling plus the potential of severe hypothermia affects the ability to think.
There may have been some collapse of snow on the ravine four and I have suggested a snow cave collapse given the amount of snow that was above them but I know it's not a perfect solution. The ravine 4 location , body positions and injuries are one of the most difficult things to explain with any of the theories although the autopsy reports seem to suggest crush injuries .
I would think Zina , Igor etc would be starting to fail and if they lasted the longest it may just be the luck of DNA or being female and carrying a bit more fat cells with strong will power to save the others . It was probably a crawl back up the slope if this is what they were doing , there would be no choice .
There are numerous examples of people and other Soviet hikers failing in similar conditions from hypothermia, some make it against the odds , others don't .