Barack Hussein Obama lectured voters during the campaign about the need to make sacrifices for the environment. But now it’s warm and toasty in the White House — so much so that aides have likened it to a tropical hot house — and Obama is under fire for turning up the heat.

Obama made climate change a staple of his stump speech last year, calling on Americans to lower their energy use and set a model for the rest of the world in combating climate change.

During a campaign event in Oregon in May, Obama said we have to “lead by example.”

“We can’t drive our SUVs and eat as much as we want and keep our homes on 72 degrees at all times,” he said.

“That’s not leadership. That’s not going to happen.”

But for the first few weeks of his presidency, that’s precisely what has happened in the White House.

On the first day of his presidency, Obama allowed staffers to venture into the Oval Office without wearing coat and tie, which had been obligatory under President Bush. Fashion observers called it a new age of business casual at the White House.

Obama’s aides had a simpler explanation. Though he’s spent more than 20 years in Chicago, the president was born in Hawaii. And so he “likes it warm” in the Oval Office, said Chief of Staff David Axelrod.

“You could grow orchids in there,” he told the New York Times.

With few orchids growing in the heartland, critics are saying that Obama — who urged individual sacrifice in an inaugural address that called for a “new era of responsibility” — hasn’t been willing to bear the cold with the rest of the country.

“It’s stunning hypocrisy,” said Christopher Horner, a senior fellow at the Competitive Enterprise Institute and author of two books critical of global warming activists.

“Obama spins the dial up, takes off his coat and seeks to mandate that we turn the dial down,” he said.

Obama’s White House declined to comment on the president’s personal energy use, but did note that his stimulus package will continue the greening trend, paving the way for 75 percent of federal buildings to be modernized to increase their energy efficiency.

Yet in the sanctum sanctorum of executive power, Obama has kept it steamy — literally. Indeed!