The vaporization of a human body is not a first order phase transition. Therefore, there can not be a unique number corresponding to this process.
The vaporization of the human body would include many components and many irreversible processes. Therefore, it could not even be characterized as a reversible process.
A first order phase transition has a well defined temperature. For example, the vaporization of liquid water at atmospheric pressure is very close to the triple point of water (100° C). However, even this isn't too sharp in real life since the system.
In a human body, there would be several substances each with a different vaporization pressure mixed together in solution. Each would vaporize at a temperature that is slightly shifted from their neat vaporization pressure. As each substance vaporizes, the vaporization temperature of each component will shift continuously. Therefore, there will be a sliding ramp of vaporizations. Thus, it couldn't possibly be characterized as a first order phase transition.
Chemical reactions would occur as the body heats. Protein would denature, for instance. Some organics will oxidize, both because of ambient oxygen and because of oxidizers in the cell. Most of these chemical reactions would effectively be irreversible. Therefore, this would not be a very clear phase transition at all.
Consider the cremation of a human body. Usually what is left is ashes. However, the chemical composition of those ashes will vary with the details of the cremation. Therefore, the vaporization of the ashes couldn't be well defined.
The question that you asked is not well posed. Maybe you want to restate your question.