To Make a Hero by Randall Garrett

Hale did not feel well at all. He kept putting one foot in front of the other, pushing himself through the blue sand, but he would much rather have crawled into the shade and gone to sleep. His brow was feverish, and his arms and legs and neck felt stiff. It had been two days since he had been caught in the rain, and his sniffles and sneezes had developed into congested lungs and a stopped-up nose. He felt like hell.

The sun was low in the evening sky, but the air was warm and soothing. He was quite a distance from the mountains now, and there was no longer much of a fog at night.