The problem is that the higher levels of potassium stop the heart from beating faster, which it would naturally do, such as when there is a loss of blood pressure. (dog-health-guide.org)
In fact, a vegan diet that is full of whole plant foods and low in healthy fats has been scientifically proven to not only stop heart disease, but actually reverse it. (rawsomehealthy.com)
Such a quick temperature change would stop the hearts of most other animals, including humans. (sciencemag.org)