Hi Magnolia....I thought the same...having the plastic heat up, even just to 75 or 80 degrees was something I thought wouldn't be great to do. I know when I've had a bottle of water in the car and it's gotten a bit warmer in there (and not even that warm), I take a sip of water and I definitely taste plastic. I didn't even want to brew in plastic at all, never mind heat it up.
So...here's what I've just now rigged up...a 1 gallon glass container, with an airlock cap (can get them at wine brewing places...ingenius little things...lets gas out, won't let air in...the bottle won't explode). Put the jar in a cupboard with a light. Temperature is about 78 or 80 degrees...seems to be working good so far.
I don't really know when it's done though...don't want to open the airlock checking on it. Maybe I'll test it after about 3 weeks...how long did you brew for at room temp? Maybe I didn't have to go to all the trouble of setting up this special cupboard...I thought room temp would take forever to brew...Vinny gives the impression that it takes a very long time...I don't know if it has to be so long...but I shutter to ask any questions there...I'm really glad we have a forum here now.