Heart Rate and cold immersion

[giblets]

Why does your heart rate decrease when you are immersed for a while in cold water?

[MrMistery]

hypotermia - blood redirected from limbs to major organs - the body tries to save as much heat as possible. I see it as a natural consequence that heart rate will slow down, since blood must reach less territory. not sure if any of this makes sense, it is very late..