For smaller kits, I like to have them seperate. In my PSK/PMK combo, the medical kit is as big as the PSK! Why? Because you can die from blood loss just as fast and easy as hypothermia, and from an infected wound well as you can from dehydration.

At the next step up, my ditch kit's medical component is just as large as the "core" part of the survival kit. Never mind that I've got about twice as much "accessory" stuff as there is core kit.