In my opinion it's just too much.
Wearily, Dembei began his climb, wending his way up the incline. By the time he neared the hilltop, his protesting legs burned with fatigue.
Would be much improved if it was just
Dembei began his climb, his legs burning with fatigue before he had even reached the hilltop.
I'm not saying that second sentence is perfect but it tells you he's climbing a hill, he's tired and his legs hurt, without having to say those things.
It would help for the author to go through the whole section and look at it as: what do I want my readers to know, how can I tell them, am I trying to tell them too much, do they really need to know that? Also the tone of the book is important as to how you try to describe things.
In my view, world-building in fantasy etc is not about over describing everything, but about thinking through the layers. When a character does something, you know why, what motivates them. When someone arrives from a far off land, that land is just as real to you, with all the details mapped out, as the one in which your story is set. But it doesn't mean that your reader needs to know all that.