Are cold wraps effective?

I used to heat wrap after sessions but they would cause my flaccid to shrink back to normal size. When I cold wrap my dick does shrink immediately after the wrap, but it becomes nicely engorged after a couple minutes. If I had to explain it I would say the cold wrap causes your dick to fall below room/body temp leading to shrinkage, but when the wrap is removed the rate of bloodflow to the dick rises in an attempt to bring it back up to temp thus causing the engorgement.