The Sweet 16 of BSA Safety describe the measures we should use at all Scouting activities. The thirteenth point of the Sweet 16 is First Aid Resources(see below).
No matter what the situation, you should “Be Prepared” for first aid. Even at den meetings I keep a very small personal first aid kit on hand for dealing with scrapes and small cuts which can occur during games. For hikes and outings, a more substantial kit is required. And if you are planning a backcountry adventure, your “resources” should include having someone along with the appropriate wilderness first aid training.
From the Sweet 16 of BSA Safety on the Scouting.org website:
13. FIRST AID RESOURCES
The supervisor should determine what first aid supplies to include among the activity equipment. The level of first aid training and skill appropriate for the activity should also be considered. An extended trek over remote terrain obviously may require more first aid resources and capabilities than an afternoon activity in the local community. Whatever is determined to be needed should be available.