A mass of nearly 600,000 tons traveling at 650 miles per second creates enormous air resistance - this would heat up the reindeer in the same fashion as a spacecraft re-entering the earth's atmosphere. The lead pair of reindeer would absorb 14.3 quintillion joules of energy per second each. In short, they would burst in to flames almost instantaneously, exposing the riendeer behind them and creating deafening sonic booms in their wake. The entire reindeer team would be vaporized in 4.26 thousands of a second, or right about the time that Sant reaches the 5th house on his trip. Not that it matters, however, since Santa, as a result of accelerating from a dead stop to 650 mph in 0.001 seconds, would be a subject to acceleration forces of 17,000 gs. A 250 pound Santa (which seems ludicrously slim considering the high calorie snacks he must have consumed over the years) would be pinned to the back of the sleigh by 4,315,015 pounds of force, instantly crushing his bones and organs and reducing him to a quivering blob of pink goo. Therefore, if Santa did exist, he's dead now . . . (fat bastard).