Ziljoe, thank you for sharing these two photos.
@GlennM The snow condition on these photos are in line with the snow conditions as is seen on the right photo on the first row as available via:
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https://dyatlovpass.com/the-den as reproduced as screenprint below:

The new photos and the photo on the right above make the - classic - snowbridge theory less likely for having caused the broken ribcages.
On the garment/clothing: in theory that I have drafted, Yuri Kri and Yuri Dor have sacrificed their upperclothing for insulating the seat for badly wounded group members - Lyudmila, Semyon and Thibo - and for Alexander who had guarded/nursed the wounded while sitting in the den together.
Yuri Kri and Yudi Dor had tried to keep themselves warm while sitting in their underwear next to the fire near the cedar.
Via using the cedar as 'watchtower' during fixed intervals, both had tried to maintain - one way - communication from the tent via the flashlight to note if the situation of Zinaida or Rustem staying wounded in the tent had worsened.
With this scenario: the undressing of both Yuris, the flashlight on top of the tent, the fire next to the cedar, and the window in the cedar with a view to the tentsite, make sense as may be expected from 'rational solution oriented' University of Technology students.