I Got Steam Heat - Do You?
If you are feeling cold in your apartment, make sure your air conditioners are properly covered and that there is nothing blocking your radiators. If you are still cold, buy a good quality indoor thermometer. Listen to the weather report on the TV or radio; note the date, time and the outdoor temperature; take the indoor temperature and make a note of it. Keep your "heat log" in a notebook devoted solely to this purpose.
If your landlord is not providing adequate heat, you don't need me to tell you to call the landlord, managing agent and/or super. In addition to calling, write a letter and send it to your landlord by certified mail, return receipt requested. Of course, keep a copy of the letter, and certified mail documents, so that you have proof that your landlord received your complaint. A phone call or letter stating "it's December 12th at 3pm and only 50 degrees in here" is a lot more effective than simply stating "it's cold in my apartment."
If your landlord does not respond to your complaints, call the New York City hotline (311) and complain. The Department of Housing Preservation and Development (DHPD) of New York City will send an inspector to your apartment with a thermometer to check the heat. If the heat is inadequate, the inspector will place a violation and DHPD will give your landlord notice of the violation. If your apartment is still cold, then go to the housing court in your borough, tell the clerk you are "pro se" (representing yourself) and start an "HP" proceeding, or call an attorney for help. Be sure to bring your heat log to court with you!