What color is your blood. Red, right? Well, actually, yes. So why does
it look blue when you see it through your skin? And is everyone's blood
always the same color red (spoiler: no)? Do all animals have red blood
('nother spoiler: no!)? And why is red blood red anyway? Hank gives you
the facts on vampires' favorite
Hank makes it all better by explaining the biochemistry of pain -- how
it works, why we have it, and how painkillers, whether they're over the
counter or heavy-duty prescription bad boys, make the pain go away.