I had some small gel ice packs ready to go, just couldn't be bothered pulling the motor out and putting the ice packs around it.
The gel packs were defrosted, then an old motor can put between them then re-frozen(With a rubber band holding it all together). It meant that the can would be completely enclosed with icy gel pack if I had used them before a race.
Looked like a donut, just little frozen packs held together with the rubber band.
A better idea than just leaving an ice cube on the motor, I just never liked the idea myself.