Physical Danger
If you've got a cushy photography job (cushy as in "safe"; not cushy as in "well-paying"), then your biggest worry is some neck and back trouble down the line from lugging your equipment around. But much like in the previous section, the danger could increase depending on your location and subject matter.
If you're sending back front-line photos from a war zone, or exploring previously unexplored parts of the rainforest, or seeing just how close you can get to that tiger to take its picture, well, you're obviously compounding the danger factor. No matter what you're taking pictures of, you should brief yourself beforehand on the possible dangers you'll run into along the way.