North Chicago Heat Ordinance

Hello, I had a question regarding the heat ordinance and can't seem to find any information from the city about the equipment that is deemed ok for meeting the ordinance.

The studio that I am in only has a gas fireplace. Just for clarity, it's not a built in but a standalone unit which is connected to a gas line. Besides this fireplace there is nothing else to provide heat so when I come home after being at school for a long time the temperatures can be as low as in the 30s since I'm not going to leave the fireplace running while out.

Does anyone have any more information on whether this is a violation?