ABSTRACT
The ambiguity arises because speaker B could mean either that he is feeling somewhat ill or that he is simply a little tired (as was the case in the interaction recorded here). Speaker A has understood the utterance to mean the former, hence her reply. Context may ordinarily be relied upon to clear up that ambiguity, but here the context was a routine greeting in an office, where one might indeed have reported for work while feeling either ill or fatigued.
