Luke.CageWhen it comes to measuring temperature (and humidity) over a long period of time, there is no such thing as small, accurate, and cheap. Even though you're not looking for a humidity reading, you may want to look into SensorPush. It's a small temp/humidity sensor you could put in each theater and read them all from an app on your phone. ....http://www.sensorpush.com/products/ht1