Desperados of the Badlands by Paul Di Filippo

When out on a field mission, Ruy Lambeth, cultural expert for UNESCO, relies heavily on his smart synthetic skinsuit, almost like a useful symbiont. But when he meets a passel of outlaws in one of the most forbidding regions of North America, and discovers that their skins are superior to his, he has to figure out how to overcome their superior numbers with his ingenuity and expertise.