The battery sits at the very bottom so it may not even be a big issue, but for what it's worth my Volt runs the coolant through the battery even when it's parked and passes some heat threshold in the battery
It may need to be plugged in to do this (mine's almost always plugged in at work), but mine definitely kicks on the coolant fan and I assume the pump when it's hot outside at work
People tell me all the time my car's running in the parking lot, the first couple of times I went out and checked but now I just say thanks
