Here's why:
* Predicate Adjective: A predicate adjective modifies the subject of the sentence and follows a linking verb.
* Linking Verb: The verb "felt" in this sentence is a linking verb because it connects the subject ("pit crew") to its description ("hot and grimy").
Therefore, "hot" and "grimy" are describing the subject ("pit crew") and are positioned after the linking verb, making them predicate adjectives.