PORTLAND – When the wind howls, the snow flies and the temperature hovers around zero, Tom O’Connell is in his element.

A veteran fuel truck driver for Downeast Energy, one of Maine’s largest heating oil companies, O’Connell dons his long johns and heavy coveralls and logs long hours to ensure that his customers in Portland’s most densely populated neighborhoods keep warm.

O’Connell welcomed Gov. John Baldacci’s emergency proclamation on Thursday aimed at triggering a federal waiver to permit drivers to work longer hours to prevent heating oil tanks from running dry during the prolonged cold snap.

“This gives me a chance to work more days. It helps us and it helps the customers,” said O’Connell, who has driven fuel trucks for more than 15 years. “We don’t want to see anyone running out of oil, especially the elderly.”

O’Connell already has been working six-day weeks and logging close to the 60-hour maximum and now expects to see that increase to 65 hours or so while the weather remains frigid.

The governor’s proclamation said fuel oil is in heavy demand because of the cold, and supplies have lagged behind demand.

It warned that a lack of deliveries would threaten public health and safety because of the bitter cold. In Portland, the temperature has been below freezing since Jan. 14 and has dipped below zero three times.

There were no plans afoot in either New Hampshire or Vermont to seek waivers similar to Maine’s.

Downeast Energy’s South Portland office was so busy that its general manager, Mark Lodge, spent some time behind the wheel of a fuel truck to ease the workload on his 18 drivers. It was the first time this winter that Lodge made deliveries.

The sustained cold has increased the already heavy demand for fuel, he said, while recent snowstorms – both large and small – have slowed traffic and made it more difficult and time-consuming for drivers to navigate slippery roads.

Higher oil prices also are a factor. Lodge said his “will call” customers – the 35 percent not on automatic delivery – are requesting smaller quantities of fuel because of the expense, and that forces drivers to make more frequent trips.

Most residential customers burn roughly 1,000 gallons of heating oil a year, he said, but the period between December and February accounts for more than half the total. Under current conditions, it’s not unusual to have to refill a standard 275-gallon tank at three-week intervals.

Relying on the degree-day formula to assess customer needs, Lodge aims at refilling the tank when 180 gallons have been consumed, providing a cushion to avert a “run dry.”

The midday temperature had barely climbed into double digits as O’Connell made his rounds. He was en route to a routine delivery when a dispatcher relaying word of an emergency “run dry” at a multi-unit apartment building on Mellen Street prompted him to shift course.

After finding a parking spot in front of the building, he placed the 150-foot-long hose over his right shoulder before vaulting a 3-foot snowbank and dragging the hose to the fill point near the back. O’Connell filled the tank with 275 gallons, then headed to the basement to prime the furnace so it would start up.

Then it was back to his deliveries, one that puts O’Connell on the road at 7 a.m. and keeps him busy until 5 p.m. But he’s not complaining about the long hours.