Continuity mistake: In this episode Cole has a mole that is found to be cancerous, the mole is not seen in any other episode. He is topless in many episodes and the mole is not in any other one.
Continuity mistake: When Kelso and Cole are sitting in the bed talking, watch the position of Kelso's arms and the juice box he is sipping from. The juice box, straw, and Kelso's arms all move around from shot to shot for the entire scene. Towards the end of the scene there is even one point where Kelso puts his arm down, the shot changes, and Kelso puts his arm down again.
Answer: Dan was drinking beer and Cox feared that Dan might get so intoxicated he would fall asleep and drown in the tub.
Mortug