I moved my fish by putting them in a tupperware-type container with water
from their tank, and then added water from the other tank a bit at a time to
set the temp and it worked. I have tried using sandwich bags, too. Use
Ziploc, though since cheaper brands don't do the trick.

As for temp, I don't use heaters. My house is fairly warm as it is and the
tanks stay around 74/5 degrees anyways. I just got some Angel's however, so
I'll probably have to dig the heaters out now. LOL.

Hope this helps.

Tammy