Okay, well 66lbs is 29.937Kg. If you multiply the amount of medication which is 20mg by the amount of kilograms which is 29.937Kg, that equals 598.74mg. 598.74mg divided by 8 hours= 74.8425mg. According to my calculations, 74.8425mg every 8 hours. You might want to round my calculation to the nearest tenth as well. I hope I am correct.
burn effects like blisters are caused by heat, not temperature. So basically that steam at 100 C contains more heat than water at 100 C but More severe, burn effects come from the gaseous water than the steam.
hopefully this helps, and i deeply apologize if i got this wrong for you