i can see this ending in one of three ways either their gonna get tired in the center and both will survive. they'll get tired and one of them will get cooked. or the batteries will eventual die and they'll survive that way
Doubted they know where the middle is. Besides, the middle could be still too hot, they know they can push further to have more comfortable distance, so they do it.
Batteries? that's an electric oven, it's plugged on the wall.
Plus it's an oven, even if it may appear "more comfortable" after pushing the wall far away, sooner or later their own zone will heat up enough to kill them, so I doubt anyyu will survive this.
There is also the whole obvious factor that "if someone puts them there" even if one survives, that survivor will probably be killed by the abyuser that puts them there, because only "that type" of abyuser would put yu's in this contraption.