When the mercury drops, backyard chickens don’t demand much.

With fluffy feathers and smaller combs atop their heads, many popular breeds — Rhode Island Reds, Buff Orpingtons, Ameraucanas, Barred Rocks — are built to weather the winter months just fine, said Jolene Whaley of Jax Ranch & Home in Fort Collins.

“Chickens are extremely hardy for the most part,” Whaley said.

It’s when chicken owners try to do too much for their hens that disaster can strike. Think faulty electrical wiring, improperly installed heat lamps and straw bedding.

Over a two-week period in December, firefighters in Wheat Ridge responded to three backyard chicken-coop fires, resulting in nearly $60,000 in property loss and 11 dead birds, the fire department said.

In Lafayette, a large chicken coop that housed 70 birds burned to the ground that same month. The coop was being warmed with a gas heater, the Boulder County Sheriff’s Office said at the time.

It may sound cold, one local chicken expert said, but heating your coop is not only unnecessary here, but could also pose a greater danger to your flock than the frigid temperatures if done incorrectly.

“The only thing chickens need to survive extremely cold weather is a place to stay dry and out of any breeze, wind or draft,” said Curtis Utley, a research associate at the CSU Extension Office in Jefferson County. “Any heat element is sure to cause a fire eventually.”

In Wheat Ridge, all three recent fires were caused by bad electrical work or heating elements, said Lt. Robert Sprenkle, deputy fire marshal for the fire protection district.

In one case, power had been run to the coop using just an extension cord and power strip, he said. In another, investigators believe a clip-on heat lamp was to blame.

Most coop bedding, insulation and bird feathers can easily ignite when in proximity to a heat source such as a heat lamp or space heater, Sprenkle said. The radiant heat alone can be enough to cause a fire, he said.

“If you need to heat your chicken coop, it would be my suggestion to hire an electrician to wire your chicken coop properly,” Sprenkle said. “Heating lamps, one, they need to be secured properly so a chicken cannot knock them down and, two, they have to have proper clearance from anything that could catch on fire.”

Whaley, manager of the pet and equine department at Jax Ranch & Home, said she hangs a heat lamp in her 6-foot-by-6-foot coop only when the temperature drops below zero.

But she said they don’t recommend lamps at all in the smaller coops on the market today, in which chickens climb a ramp into an elevated area.

“It’s so tight in there,” Whaley said. “If the light got too hot and caught fire, that would be really bad.”

During winter months, she said, one thing a chicken owner can do is change the type of bedding in the coop — straw is a better insulator than wood or paper products.

James Bertini, owner of Denver Urban Homesteading, an urban agricultural center and market, said he knows of many urban chicken farmers who use heat lamps, both to keep their birds warmer and to provide additional light to keep egg production up during the shorter winter days.

His own flock, though, goes au naturale, with some extra attention paid to keeping the coop door closed on truly cold nights.

“Chickens can and do survive in this climate,” Bertini said. “It’s just a matter of personal preference.”

To keep egg production going, Utley suggests installing a low-wattage compact fluorescent bulb in the coop instead.

“If you want to keep a chicken laying eggs through the winter, you have to give them some light,” Utley said, noting they need 16 hours a day. “They don’t need a lot of light, just 25 watts.”

A properly constructed coop should take care of nearly everything else, he said. Air still needs to be able to circulate or vent, even in the winter, high at the roof or rafter line.

If you’re not going to heat the coop, both Utley and Bertini said you do need to keep an eye on the chickens’ water to make sure it doesn’t freeze.

Utley uses a submersible birdbath heater to keep the water frost-free. Bertini replaces water daily as part of his morning routine.

Emilie Rusch: 303-954-2457, erusch@denverpost.com or twitter.com/emilierusch