I work not only as an EMT, but I also work on what's called a lift team. We work exclusively in a hospital, and are paged to go to different patient rooms and, well, lift them. Fortunately, the advantage of working in the hospital is we often have mechanical lifts, so we don't have to lift the patients manually all the time. However, there have been some individuals who exceed the lifting capacity of many of our lifts. In these situations, we call in an extra lift team, and get the help of RNs and NAs. In one situation, we had 8 people lifting an individual that I estimated to be about 700 lbs, just long enough to slide an X-ray board below them.
Many of patients that I encounter are ashamed of themselves for letting themselves get so large. In fact, many of them appologize to us. The fact of the matter is, many of them have some deep rooted physical or mental issue which contributes a great deal to their weight gain. Perhaps if more people would focus on this, then there wouldn't be so much negativity directed towards such patients.