Ignoring the legal ramifications, and ignoring your job or need for one, but looking at a "crisis situation" such as a natural disaster, riot, ect.. (Let’s just look at a Katrina like event)

One of the key points that a majority of the people on this site (and that I feel is accurate) is that when things go sideways during a natural disaster, you want to be the "grey man" meaning you don't want to attract attention of being over prepared or seem like you have things that others want. You don't necessarily want to be the person with there lights on watching TV on there flat screen TV in there living room when the entire neighborhood has no power and some have lost there house to weather or circumstance. People have a tendency to take notice.

So if it is 100 degrees out and the nature of the environment makes you feel like the vest is necessary the first thing people are going to notice is that you look like the stay-puffed marshmallow man due to your vest, then people may start to wonder is, "what does that person have that they need to protect themselves so much?"

Now if it is mid winter and heavy coats are the nature of the beast, you will just look like you are supper cold.

I am not going to pretend to know al the laws and the legal ramifications of a vest. But I can say that you will draw attention to yourself, and that attention may not be wanted.

This site isn't an "end of the world as we know it" site. From what I have seen most people on this site seem to express that society will return to normal at some point and that things will get back together.