As temperatures drop, state lawmakers are considering changing the laws around one unfortunate approach to a heavy night out: sleeping in a car.

A law passed by the Senate would carve out exceptions to New Hampshire’s driving while intoxicated laws to allow people who have drunk above the limit to sleep in their cars.

Advocates say it’s a necessary change to prevent those trying to sleep off their intoxication to do so without fear of being charged by a passing officer.

But while the idea has caught on in the state senate, where the bill received unanimous approval, House lawmakers are less sure. Some members of the House Transportation Committee have doled out strong skepticism.

“I don’t want to be overly melodramatic, but we’re playing with persons’ lives here,” said Rep. George Sykes, the committee chairman, at a work session on Tuesday.

Sykes, a Lebanon Democrat, called the bill “replete with problems,” warning that it would give a green light for intoxicated people to sleep for a short period of time and drive home drunk anyway. And he questioned how widespread the problem is to begin with.

“It’s going to take a long time to convince me that we need to monkey with something that may only be a problem for a very small number of persons.”

Senate Bill 34 would amend the definition of “operating” a motor vehicle while impaired by drugs or alcohol — adding certain exclusions.

“Driving,” “attempting to drive,” or “actual physical control” would not include anyone who is sleeping or sheltering in their car provided the car was parked lawfully; anyone who didn’t have the “intent to control the vehicle in a manner which could pose a danger to the public”; and anyone sitting in a vehicle that is inoperable.

Under the proposed law, as long as someone doesn’t have the “intent” to drive, a passing police officer can’t arrest and charge them, even if the ignition is on.

That allows people to turn on the heat while they attempt to sleep off their alcohol, supporters say.

To Rep. Steven Smith, a Charlestown Republican and former chairman of the committee, the bill would allow those intoxicated to do the right thing without being penalized.

“If they want to go in their car and sleep it off, don’t be behind the wheel,” Smith said. “Be in the back seat, be in the passenger seat. I would think that if I did that, and climbed into the back seat of my car or a pickup truck without a pass-through, I would have established that I did not mean to attempt to drive. And for doing that, I don’t think they should be arresting people.”

But opponents — who include the New Hampshire Department of Safety, the Association of Chiefs of Police and the Police Association — say that that may be an overly rosy scenario.

Rep. Larry Gagne, a Manchester Republican, painted another one.

“It puts the onus on the beat cop, out there, three o’clock in the morning in Manchester, windows are cracked and motor’s running, person’s in the back seat. You wake them up: ‘No, no I don’t want to drive, I just wanted to keep warm.’ So it’s on you to make a decision.”

The consequences could be too dear, Gagne added.

“What happens if you let him go? And that person decides ‘I’m good enough to drive.’ That person takes off and gets into an accident. Hits a telephone pole. And that’s on you. Because you let him go,” Gagne said.

Some on the committee argued the burden should be on the person going out to drink to arrange a better backup scenario, whether through a friend or a cab service.

Others say more information is needed before the committee can take action. Rep. Nicole Klein-Knight, a freshman Democrat from Manchester, said she wanted to see statistics indicating how many people are arrested for driving while intoxicated despite the vehicle being stationary.

Existing statistics on DWI convictions in recent years have shown a decline, Klein-Knight said — an indication, she argued, that police officers were not abusing the DWI law.

“Currently what we’re seeing is a decrease in DUIs — there’s no reason to muck that up with a poorly written law that could increase DUIs, she said.

Not all Democrats are opposed; Laconia Rep. Charlie St. Clair strongly supports the proposed overhaul.

“Somebody gets in their vehicle, and says, whatever the reason, maybe I’m tired, maybe I think I’ve had too much to drink, whatever, I’m going to be responsible now and sit in my car,” St. Clair said. “If we can craft this to say, you can sit in your car but not behind the driver’s seat, I think they’re showing the responsibility saying ‘I know the law, I’m not going to sit behind the steering wheel’… That should cut it.”

But overall, the political path for the bill looked steep Tuesday.

“The bill as it’s currently written is something I could never support,” Sykes said. “It’s badly written; it won’t do what it wants to do.”

The political divide fits into a familiar dynamic between the House and Senate. Last year, a similar bill, Senate Bill 499, cleared the Republican Senate 20-4 only to be killed in the Republican House 209-122.

Lawmakers in the committee are working to tweak the language of the bill before making a final decision and passing it to the full House next year.