What is the description of Chamberlain?

From the text:

Chamberlain looked up through bleary eyes. He had walked eighty miles in four days through the hottest weather he had ever known and he had gone down with sunstroke. He felt an eerie fragility, like a piece of thin glass in a high hot wind. He saw a wooden canteen, held in the big hand of Kilrain, cold drops of water on varnished sides. He drank. The world focused.