Dad has been taking out of ICU. He's no longer spiking fevers, his blood levels are not dropping (although they aren't improving, either), and he feels basically pretty good. His condition has been downgraded (basically meaning he's not critical anymore).
Unfortunately, we don't know exactly what caused this. So far, the cultures haven't grown anything (although there's still a chance we'll see something by midnight tonight), and there aren't any good theories being advanced. This will likely cause Dad to hang around Arlington for an additional 5 - 7 days.
I don't know of a way to contact him short of telephone, and I'm hesitant to open the floodgates of callers so I'll be releasing information here as I get it. As such, I won't be making daily reports (like this one), just sending out highlights. He's doing well, we just don't know why he had this problem.
You may compare today's report against the last report.