[smokey mac pot]

i am having to change my growing place from indoors to out becuase my mom has her suspitions and if she intercepts the mail then im 40 nucks in the hole. im changing to green house growing. there is this one green house close to me. its abandoned. if i were to have a way to make sure no one stole my plants then what else do i have to worry about? the place is abandoned but the lights and the ventilation system still work.the last time i was in there i left the vents on to cool it down in there and vent out the smells. im am worried about watering and varmits and theft. its very hot in there, last time i was in there it was aroung 90 to 100 degrees because i automatically started to sweat. but it has a control thing that make the heat lower. do i have to worry about heat? in there it has a plastic like garbage bin thats empty. if i were to get a peice of plywood to put over the bin could i put dry ice and water in a bowlp atnight when i check up on it? i heard that in the forums that dry ice helps.then in the moring i could take off the ply wood and if the ice is still there just leave it there if its almost gone or save it for later. then water it and check for varmitts. i am clue less about green house growing