98 Civic LX heater smells like fire! anyone?

[Yoshi]

So I just got a call from my sister.
Her 98 Civic LX is somehow screwed up, and since she's on the other side of the country, I can't take a look at it in person.

The Problem:
Her heater smells like a campfire when turned on. Regardless of whether it's set to recirc or fresh air (vent), the smell remains; and once the HVAC system is turned off, the smell begins to fade. There is no smoke. There are no odd engine issues or different exhaust smell/color. I'm figuring something is melting/burning next to one of the HVAC hoses, or maybe it's the hose itself... but then you'd think it'd smell like burning plastic or rubber... no. It smells like a camping trip

This one had me scratching my head, and my sis is afraid to go very far with the car running as it is. I'm stumped w/o being able to look at it so I'm calling for re-enforcements from the masses of zilvia... I know it's not an S-chassis, but hey, it's OT right?

Thanks in advance to anyone that can assist.