With Karl, Hawk, and the sword all adding heat to the cave, it warmed up quickly, and they were able to comfortably hang the hammocks using Rae's web to attach them to the walls.
There would be no sleeping on the cold floor for his group, and they could get away with a minimal watch, as there were artillery battalion patrols ten metres outside their door.
As they finished dinner, Karl noticed that the patrols were lingering outside the entrance to the cave, which was located about a metre above ground level, and four metres above the cavern that they were in.
The stone walls of the cavern were already warm, not frozen by the suddenly frigid air outside, but with the flames they were using for heat, Karl suspected that the guards were lingering where the warm air was venting before moving on with their patrols.