One of the best pieces of field and survival gear you can have is a way to quickly communicate with the outside world. A cell phone is ideal as long as you have phone coverage.
Along similar lines, a great piece of tactical gear is a GPS unit. This should work no matter where you are as long as the batteries hold out, and you can keep from ever becoming lost.
Knives and swords are both helpful, though knives are easier to carry. You can use these to clean fish if you need to eat or to build a lean-to out of small tress and branches.
This will give you a basic way to fix minor injuries. You will not be able put a cast on a broken leg, but you can make sure a minor injury does not lead to major complications.
People are often thinking so hard about what tactical gear they need that they forget the basics. You have to have water to prevent dehydration and heat stroke.
Along similar lines, some of the best survival gear you can have is also the most obvious. You want to have food that is in packaging and can be rationed out for a long time if you are lost.
As mentioned, a knife can be helpful in this process. It is also a good idea to have a poncho or some other sort of garment that you can use to keep off the rain.