I think that this question is on topic for this site as it states human physiology and pathophysiology is allowed. If not then please let me know in the comments and I shall delete this Question. Please let me know where this question would be better suited if possible.
A google for an answer to this mainly comes up with answers to why we shiver, and not to how much we heat up and what the different factors that affect this are. For instance does height, weight, and/or body fat percentage affect this? How much energy do we use to shiver and does it burn fat?
I'm asking in relation to when we shiver randomly, quickly, not continuously, as well as when we are cold and when we our body goes under rapid change in temperature (i.e an emergency blood transfusion with cold blood).