Although it is often mentioned as a symptom it seems to be not addressed.
I experienced life long B12 deficiency and have mitigated the body temperature regulation my whole life and am good at it.
I am finding that regulating my body temp is now healing in that it gives my body less to do.
When I am out in the cold I dress very well and push through until my body "heats up" from movement. If inside I take a warm shower and use an electric blanket. Sometimes I go for a long drive with my heat on full blast.
When it is cold I use AC and a fan.
My go to that seems the most effective is open water swimming followed by hot shower. Pool or open water. The best is open water on a hot day then dry in the sun.