I was just looking in Mission Cockpit to see if this is one of the stats it can report using the speech module, unfortunately its not in the list in the version I have. Would be a nice upgrade to M/C to have it be able to call out the BL temps as you're flying. I have it setup on my netbook to report battery voltage, altitude, and distance from home as the Mk flys, nice to be able to just concetrate on the flying and have the computer tell you what's going on with the MK.
Heatsinks on the BL's are a nice idea though the problem with that is if you do install them they must be glued on with thermal epoxy which essentially makes it impossible to ever change a FET if one goes out. I wouldn't consider using them without gluing them down, if one happens to fall off and short some components you could lose a lot of expensive electronics, not just from the short, but also from the resulting crash.
Ken