ATHENS — Even in the leafy northern stretches of this city, home to luxury apartment buildings, mansions with swimming pools and tennis clubs, the smell of wood smoke lingers everywhere at night.

In her fourth-floor apartment here, Valy Pantelemidou, 37, a speech therapist, is, like many other Greeks, trying to save money on heating oil by using her fireplace to stay warm.

Unemployment is at a record high of 26.8 percent in Greece, and many people have had their salaries and pensions cut, but those are not the main reasons so few residents here can afford heating oil. In the fall, the Greek government raised the taxes on heating oil by 450 percent.

Overnight, the price of heating a small apartment for the winter shot up to about $1,900 from $1,300. “At the beginning of autumn, it was the biggest topic with all my friends: How are we going to heat our places?” said Ms. Pantelemidou, who has had to lower her fees to keep clients. “Now, when I am out walking the dog, I see people with bags picking up sticks. In this neighborhood, really.”

In raising the taxes, government officials hoped not just to increase revenue but also to equalize taxes on heating oil and diesel, to cut down on the illegal practice of selling cheaper heating oil as diesel fuel. But the effort, which many Greeks dismiss as a cruel stupidity, appears to have backfired in more than one way.