Hi Im new here, let me tell you a little about my car

I have a 99 Acura Integra LS that has 44k miles on it. I do regular maintence, oil changes, brake fluid, tranny fluid checks etc.

My problem is now that when Ive driven my car a few minutes and I come across a sign or light to stop fully, this burning smell comes out of the air vents. My car doesnt run hot. Im not sure what the problem could be?

Any ideas??