No, they can just tell. Im guessing its something with the electromagnetic fields and the orientation of the plants.
ITs been proven time and time again, however if you wish to test it for yourself, go right ahead. Its been tried countless time
with the same results. (Also, the plants just respond better and look so much more lush if left to their own devices.)
Either way, you need to avoid messing with the roots in the first place. The more wet you keep ANY plant,
the more you invite root rot and fungus. you need to keep the plants cooled for hours at a time, not cool it for an hour and
hope it stays cold. this can be done using swamp coolers or extensive greenhouses.
(PS - take your idea off of cooling the plant itself. Try to cool the air around it)