If you don't have a heat lamp yet, and you don't want your coastal to be cold, put him in a click clack inside the
bredli's enclosure, but don't put a water bowl in, in case the
bredli tips the click clack up and it falls on the coastal. You will have to take the click clack out daily and give the lil fella some water tho.
I know this is not a long term solution, and it might razz both snakes up, but at least you'll still have 2 snakes!
Better yet, go get the heat lamp (and cover) and put your coastal in his own enclosure... altho, as a hatchy, it's probably best if he's in a click clack. It will probably make him feel more secure and less vulnerable.