Everyone gave great advice regarding loosing power.
As far as tornadoes, when we lived by Chicago our plan was having tubs and heat packs set aside so we could bring the snakes with us to my parents because we didn't have a basement. If one hit and our home was destroyed I would to contact other herp friends in the area that weren't affected and bring our animals there and set them up temporarily. Now, luckily we have a basement and if one hit (which I don't even know if Colo Sp has tornadoes) we would stick to our original plan.