The House Hargen live on thin ice, on their amphibious steeds, the ice toads, they dive between openings in the ice and many of their warriors have surgically implanted face masks to help them breath underwater and protect them from the cold water.
While it is an advantage, it is a permanent implant and it means that they cannot chew regular food and must live off soup and fish paste poured into a tube in the apparatus. The masks are not standardised each has been created specifically, at at some expense, by the owner.