“[As they’re checking Ronald Reagan’s vital signs]…they’re already putting tons of fluids into his body through IV lines: that helps increase blood pressure. As this is going on, a nurse can’t even detect his blood pressure: it’s that low, he’s lost that much blood. By the end of the day [he] had lost more than half of his blood volume,” says Del Quintin Wilber, author of Rawhide Down: The Near Assassination of Ronald Reagan.