The contrast range in nature from bright to dark is far more than can be captured on film. To a great degree, our eyes adjust to the brightness changes so we don't notice it that much, but rest assured your film (or digital) will. You can use the spot meter built into your camera to help evaluate the brightness in various parts of the frame, but if you've ever wished for a way to quickly assess a scene, this tip is for you.
Squint. Yup, I said "squint." This will turn the entire scene into shadows and highlights. Much of the color and detail will disappear. If you loose detail in the entire scene, you will probably be OK. Any unusually bright "hot spots" though will stand out plainly. If you do find yourself with a high-contrast situation, you will need to either rethink things or take steps to reduce the contrast within the scene with a graduated neutral density filter, fill flash or other means.