If you need to worry about "spot" temp changes, I'd say that you have an incredibly delicate species. In nature tempurature,(esp land, vs water), changes drastically. Should the variations in temps that you are concerned about be responsible in wiping out all, of any/all, species, our planet would be defunct of everything but ourselves. Keeping them within the suggested/applied temp ranges should be enough to suffice your worries. Also, you need to observe your animals 24/7 to see how they respond. Since you are so concerned (which is wonderful) - get out your notebook and jot down the info you have, and your experiences, - very valuable. Let us know what you have discovered, and good luck to you and animals.