the official sequel to Carpenter’s The Thing was a videogame. it continued the story after the closing scene of the movie.
http://en.wikipedia.org/wiki/The_Thing_%28video_game%29
however, if you look carefully at the ending of the movie, some think you can see the answer for yourself. here’s a hint... what does human breath look like in cold weather? ;)
https://www.youtube.com/watch?v=GA4Ozqt7338
other theories here:
http://www.reddit.com/r/movies/comments/267cx8/the_thing_1982_ending_mystery_potentially_solved/
Just watched the ending again from your link. It’s hard to see, but Child’s breath is visible near the end before he drinks from the bottle. I think the lighting hides his breath before then.
I do think the bottle that Child’s drank from contained gas. In that moment MacReady knew that Child’s was the Thing, and he let out a quiet chuckle.
OK, I;’m going on a limb here. So basically Chiles was the alien due to the continuous breath that McReady produced on the final scene?