I went home yesterday to grade on the couch, and just couldn't get warm. You know the feeling, just cold through and through, and can't get warm. It's been coming on for me over the past day or two; I've woken up okay, but in the evening just feel like I can't get warm. Bad cold coming on.
Then this morning, I woke up at 4am, almost shivering under my quilt and blankets. I eventually forced myself out of bed for some hot tea, wrapped in a blanket, turned on the space heater, and tried to get warm with little success.
I decided to give in and turn up the thermostat, and there, lo and behold, it said the house was at 56F, because the batteries were low.
It appears that I've found the cure for the common cold, and it's two AA batteries.