I've never had any problems with my horizontal nipples freezing. After reading what everyone has to say here I think I know why. Just plain dumb luck. The nipples holes were drilled up from the bottom about 3 inches. The tote I use for water is sitting on an old foot stool from a living room chair. I think the insulation provided by the padding of the stool plus having the nipples up a little bit has kept my waterer working even at -22 F.