2002 Ford Escape heater

Chances are that your heater core (on inside of the car) has developed a small leak. This leak allows antifreeze into the car and the heat of the core tries to burn it up causing a chemical smell insde the car coming from the HVAC vents. Feel around the carpet under the dash board to see if you can feel any moisture. If the leak is substantial it will drip onto the floor board and ge the carpet wet. Heated Antifreeze make a bad chemical odor inside the car when hot.

With your low milage it does not seem likley but the years on the car can reason the leak.

If it is the heater core you will need to replace it as you will loose water from the radiator, have a bad smell and soak your carpet inside the car.