You might find this old thread informative.

My response is still the same as back then--you don't have a whole lot of options in an apartment beyond trying to create a small space that you can try to keep insulated and warm. I think it's best for an apartment dweller to have a secondary place they can bug out to for an extended cold scenario, if that's possible.

Since apartment dwellers have fewer practical heating options, they can resort to dangerous methods if they get desperate about the cold. I'd hate to die of CO poisoning or a fire because residents in another apartment are doing something dangerous.