What does the man wear in Jack London's "To Build a Fire"?

I think, given the setting of this excellent story of
survival, that we can safely assume he wasn't wearing a swimsuit! If you look at the
text carefully, you can see that in the opening paragraphs of this story the dress of
the man, who interestingly remains nameless, is described to us, in a paragraph that
also makes clear the man's central failing in underestimating the power of
nature:

Fifty
degrees below zero stood for a bite of frost that hurt and that must be guarded against
by the use of mittens, earflaps, warm moccasins, and thick socks. Fifty degrees below
zero was to him just precisely fifty degrees below zero. That there should be anything
more to it than that was a thought that never entered his
head.

Thus, obviously, the
man is dressed extremely warmly for the weather, but also note how this paragraph makes
it clear the limitation of the man in treating the temperature and the intense cold very
literally and precisely, being blind to the might of nature and the inherent weakness of
mankind in response to the overwhelming power of the natural
world.