A personal medical kit is a small kit kept on-person that contains essential supplies carried by each member of a trip.  They are beneficial in that they provide redundancy of essential items in case another member's personal kit or parts of the group kit are damaged, lost, or stolen as well as being accessible to the individual should he/she be separated from the larger group. This kit should also include personal identification, medical identification, and any supplies or medications necessary to manage one's own personal medical conditions.  
While no two travelers will likely pack the same items in their personal medical kit, it would be prudent to consider carrying the following practical items no matter the type of trip planned:
Personal prescriptions in well-labeled, waterproof lightweight container/bag
High priority over the counter (OTC) medications such as pain relievers, anti-histamines, anti-nausea, antacids, and-diarrheals, creams/ointments, and aloe vera gel.
Copy of personal identification documents
Notepad and writing utensil (preferably waterproof paper, and a pencil)
Sun protection (hat, sunglasses, high SPF sunscreen); bring excess of sunscreen as this will likely be shared with other participants
Topographic map, compass, GPS device (and a basic knowledge of how to utilize these tools)
Multitool (e.g. Swiss Army knife, Leatherman)
Nylon cord
Small plastic zip ties
Plastic bags
Rescue whistle and small plastic mirror for signaling
Fire starting items (lighter, wind-proof matches, flint/steel)
Rain poncho, or large thick garbage bag (preferably 4mm thickness)
Adhesive compress
Alcohol-based hand sanitizer
Alcohol preps
Bandages in different sizes
Topical tissue adhesive (e.g. Dermabond)
Duct tape
Brightly-colored flagging tape
Bandana
Safety pins
Granola/protein bar for quick energy
Personal hygiene products
Condoms
Survival guide
Mosquito netting
Ear plugs (to maintain adequate sleep in unfamiliar environment)
Wilderness preparedness
ACEP clinical policies
Poison control
SCVMC:CUSTODY CARE
Ideal body weight estimation
Diagnosis of death
Pregnancy and lactation drug labeling
Baby feeding and nutrition