NEW YORK (CBSNewYork) – The extreme cold is even more of a worry for people with no heat.

CBS2’s Marc Liverman followed a very busy home heating technician around Tuesday, who said there’s no let-up in sight.

Wire after wire, sensor after sensor, for Erni Tosku, of ASE HVAC, the work never stops – especially when an entire week goes by and temperatures never climb above freezing.

“People out there are desperate. They need heat,” he told Liverman.

His first stop was Cornelia Street in Bushwick, Brooklyn, where he met Howard Tilkin, owner of a two-unit rental property.

“They’ve been miserable. There’s no heat in the basement — or the heat in the basement is insufficient,” he said.

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Fortunately, the tenants that he was referring to were out of town last week and the furnace was fixed in time for their return.

“I’ll be honest – I called Erni after a different guy cancelled on me three times last week,” said Tilkin.

He said the other contractor was just too busy.

“After three cancellations, I said I don’t have time for this anymore,” he said.

So he called Tosku who repaired a vent and a sensor.

As soon as he was done, it was off to the next job — a home in Woodmere, Long Island.

Tosku said this week alone, he’s been getting close to 50 calls a day.

In Woodmere, he was focused on repairing a motherboard and a sensor.

Some of the jobs can take close to two hours, while others can take as many as five to complete.

Sometimes you can save yourself a wait just by maintaining your heating system – things like changing a filter. Outside of that, Tosku says to leave it to the professionals or it could cost you your life.

“It’s dangerous, because it’s natural gas. And if you do something wrong – this motherboard for example, it can open the valve and you have gas all over the house, you light up something and boom,” he said.

If you have to open a furnace, remember to always disconnect the power first.