"Hai, hai! I'll send a few more of the water department down to help you remove your find." In full on investigation mode, Conan's not stopped to consider the effects on himself or consider how he's feeling. It's only belatedly once he's out in the fresh air that the reason for Loewe's adminition occurs to him and he's thoughtful as he sends him the water department staff, telling them to send him up if he looks like he needs air.

The first team down there is taking a break and Conan's got a lot to do debriefing them, and seeing their finds are catalogued then sent to the hospital lab. This thread might be wrapping up, but the investigation is only beginning.