Little tidbits from experienced doctors can make all the difference in practice.
Think of a child swimming in cold water and how they start to shiver and develop blue-purple lips, fingers and toes. I have a small spring fed pond behind my clinic. The water is very cold all year round. If I dip my feet into it, within 2 minutes they start to ache. Cold causes blood stasis and this blood stasis causes pain. However, as soon as the child is warmed up, the lips, fingers and toes turn pink again!