cold weather rabbit

I know that you can't have your rabbits in theheat (over 80*) but I was wondering if you need to worry abot coldweather. This week the low is supposed to be 24*. I bring them hotwater every hour (X-mas break) and they have a tarp covered with ablanket over 1/2 of their cage. They are getting sunflower seeds(though I am worrying that Matches is getting to fat) to keep themwarm. Other than that i don't know what to do.

Here's some good reading, bunnymother:

http://rabbitsonline.net/view_topic.php?id=1964&forum_id=1&highlight=keeping+rabbit+warm

Laura