Restaurant owners say they are worried they will get crushed when it gets colder and outdoor dining dies out.

For many diners, outdoor eating is their preferred choice.

Some restaurants in Islip have installed high-end MERV 13 air filters to help customers feel more comfortable indoors, but not all restaurants can afford to do that.

"For somebody that has no outdoor dining, to have 50% inside can be difficult. If you're busy all day long, every day, it can work. Restaurants that are just busy on weekends and really need to pack out to make the money, it's difficult than for them to do that," said Kurt Bohlsen, with Bohlsen Restaurant Group.

Bohlsen, who owns Tellers, installed the special air filter. He says the system wasn't cheap but worth every penny if it encourages more customers to eat at his restaurant.

Diner Kristi Piotrowski says the investment will help.

"I think it is very impressive that these local business owners are stepping up as much as they can just for their patrons to come back and visit," Piotrowski said.

New York City restaurants were just recently given the green light for indoor dining at 25% capacity. That will begin on Sept. 30.