Is it genetics when cold extremities run in the family? Can it be helped even at the late age of 80?

If by genetics you mean that you can inherit a weakness to a system or organ, then yes genetics can have an impact, but lifestyle and diet usually have a bigger impact.  We often adopt similar diets and lifestyle to that of our relatives.  Even if you inherit your parent’s weaker circulatory system, adopting proper diet and lifestyle can at least partially correct the situation. 

Cold extremities can be caused by a poor microcirculation, meaning circulation in the smallest blood vessels, called capillaries.  Taking Ginkgo can help improve microcirculation.  Some people start feeling some improvement in about 2 weeks.  

A slow thyroid can also be responsible for cold extremities.  The thyroid gland is responsible for controlling body temperature and when it slows down, the core temperature goes down but we notice it more in the extremities.  Strengthening the thyroid gland with Thyroid Support from A.Vogel can help prevent it from going into hypo-activity, at which point you would need medication.