It makes him feel in his game. This was taken before the scramble section. Usually he doesn't hike with it on, but in this case perhaps it was also for warmth. In winter I have used my helmet as a hat before.
"After the first glass, you see things as you wish they were. After the second, you see things as they are not. Finally, you see things as they really are, which is the most horrible thing in the world."
--Oscar Wilde on Absinthe