Smoking and leaking defrost vents

Today on my ride home I noticed my driver and passenger door window defrost vents smoking. There is also condensation built up that doesn't seem to have an odor, but has an oil texture to it. Has anyone else run into this before? BTW this is on a 1999 xj and these are just the vents above the far left and far right ac vents on the dash.

Thanks,
Shrek

Looks like google is pointing me towards a new heater core.

Heater core is leaking or the hoses going to it are allowing it to spray into the heater box.