I used the live in South Florida and it gets hot there. If it has a fan, just use it. I've had 2 pole motors heat my controllers more then multi pole motors. Your controller might work twice as hard, but the 4 or 6 pole motors will produce more torque and require less AMPs to make your vehicle move. If your fan does fail, do like jhautz did:
http://www.rctech.net/forum/showpost...postcount=6753