Decrease of pulse rate due to temperature.?

Question

When you place ice water against your arm when monitoring your pulse rate, it decreases. Why does it decrease?

Answer 1

I've not really heard of that, but it could possibly be due to paradoxical vagomimetic response the nervous system has to startling sensations, which slows the heart rate, sometimes to the degree of syncope (fainting) -- touching ice-water might qualify as such a sensation.