when you have a high fever, that is your body fighting the virus and when you sweat from a fever, it is your body;s way of cooling itself. I don't understand the sub normal temp in people but in animals it usually means they have gone through the high fever and are crashing. we get out the heat lamps and warmers to get the temp up before the body shuts down.
Glad to hear your son is better, Hoppy! Wouldn't a subnormal temperature make you feel hot, since a high fever makes you feel cold? I don't really know, just speculation.