They didn't give up hope even though they were tired and wet to the bone.

even 在这里是副词，用来加强语气，表示"即使、纵然"的意思。 though 是连词，表示"虽然、尽管"，用于引导让步状语从句。 even though 是一个固定搭配的连词短语，表示"即使、尽管"，比单独使用though语气更强，强调即使在极端情况下也不会改变结果。