I personally feel that you are better off mounting a small fan that blows on the motor endbell during your race. Much more makes one for $10.
I rigged one up for running outdoors mod on a fairly open 100+degree track. It cooled the motor up to 40 degrees less after a run than without the fan.
Plus with a very cold motor to start, you may experience a greater degree of perceived "fade" as the motor warms up.