It was cold enough, and the camera must have registered it in the way the snow was heaped upon their hatbrims, drifted upon their shoulders, packed in the wrinkles of their clothing and in the manes and tails of the horses.

And the horses certainly were leg-weary; so weary that Luck knew how the boys must have ridden to gather the cattle and to put their mounts in that condition of realistic exhaustion.
In the story they were supposed to have ridden nearly all night,--the night-guard who had been on duty when the storm struck and the cattle began to drift, and who had stuck to their posts even though they could not turn the herd.
That might be stretching the probabilities just a shade, but Luck felt that the effects he wanted to get justified the slight license he had used in his plot.

The effects were there, in generous measure.

He turned the crank on the whole of their descent and got them riding up into the foreground pinched with cold, miserable as men may be.

They did not look at him--they dared not until he had given the word that the scene was ended.
"Ride on past, down into that gully where the cattle went," he directed them sharply.