Does Heat Metal or Fire Shield have more than one damage roll?

@JeremyECrawford Does Heat Metal have more than one damage roll? Does Fire Shield have more than one damage roll?

— Eric Green (@quadhund) December 13, 2017

My guess is that Fire Shield has multiple rolls (each time you are hit, roll). However, Heat Metal specifically says "on each of your subsequent turns to cause this damage again." It is unclear if this damage is intended to be 2d8 or what the initial 2d8 damage was.

— Eric Green (@quadhund) December 13, 2017

Yes, roll again.

— Jeremy Crawford (@JeremyECrawford) December 13, 2017