Instead of offering further comment on whether or not his help is strictly needed, he washed his hands, located some gauze, and held it to the wound. Basic first aid: assess the situation, stop the bleeding, then worry about cleaning and bandaging. Don't worry about the amount of blood because heads bleed a lot. Do worry about dizziness, weakness, or disorientation.

If he ever gets home, Chekov will need to remember to shadow McCoy so he can learn more than just the basics.

He frowned, more because any conversation would undoubtedly be uncomfortable than out of confusion. "I don't know what you mean."