[tinyowl]

Wouldn't the mechanism be more like hypothermia where it's not so much dead cells bunching up in extremities but the brain pulling the blood away from extremities and sending it where it's more important?

(Not an expert, not a doc - that's just want first occurred to me)

[Pontiac]

In hypothermia the blood vessels in the extremities constrict to keep core body temperature at as normal a temperature as possible to keep the organs functioning.

This would seem to be caused by the red blood cells damaged by the virus pooling and clotting and blocking arteries in the feet.