What happened to Fuchs in John Carpenter's The Thing?

Question

In John Carpenter's The Thing, Fuchs ventures outside with a flare. Later, MacReady finds some burnt remains and surmises that they belong to Fuchs.

What exactly happened to him?

Answer 1

This question is answered in a deleted scene. Childs and Palmer go looking for him, and eventually come to the greenhouse in which they grow some vegetables and fruits - as well as their marijuana supply. There, they discover Fuchs' body, impaled with a shovel on the back of a door.

The excellent fan site Outpost 31 describes the deleted scene:

Here, the men have formed search groups to look for Fuchs who's discovered to be missing after the lights come back on. [Note: The scene in which the lights go out was also cut] Childs and Palmer are paired off together, and in the course of their search they check out the greenhouse where they have a stash of weed. They find out that the greenhouse's roof has been mysteriously ripped away, causing the marijuana crop to go into deep freeze.

_{You can see the frozen pot plants in the foreground}

Notice the door behind Palmer's back. As Palmer and Childs debate about what to do with this new problem, the door begins to swing shut. To their horror, the men discover Fuchs has been impaled to the door's backside by an unknown assailant:

I'm not sure where the burned stuff came from, but I'll try to find some more information on that part of the question. I would speculate that one of the previously assimilated Things burned its clothes, since we learn earlier in the movie that assimilation destroys the victim's clothing.