Hal Clement 
Cycle of Fire [EPUB ebook] 

Stranded on an alien planet, light years from home, wandering from blistering heat to searing cold, Nils Kruger was not a happy man. So when he met another being — even though it wasn’t human — things seemed to be looking up. The alien might be helpless, or it might be dangerous, but one thing was for sure — they stood a better chance for survival if they worked together.But as the two creatures overcame their mutual suspicion, as they worked together, as the language barrier was broken down, Nils came to a terrifying conclusion — this alien was more intelligent than a human. And to it, Nils was the alien.