For millions of Americans the rule is simple: If you don't come to work, you don't get paid.
That idea drives an untold numbers of carpenters, day care workers, servers, shopkeepers and small-business owners to their jobs each day. Sniffles or not.
As the swine flu spreads across the nation — and public health officials plead with the ill to, please, stay home in bed for several days until the fever goes away — a large segment of the American work force will face a tough choice about whether to call in sick or simply muddle through. That's because when skipping work means skipping food on the table or missing a rent payment, staying in bed isn't as simple as it sounds.
Kara Knoche, 28, is worried about getting swine flu and the money she would lose by missing a week of work. The Atlanta waitress is downing Vitamin C supplements, going out of her way to eat immune system-boosting foods and avoiding friends with the sniffles or hacking coughs.
"If you don't save up, you're basically behind and you're broke. Every dollar you make after that is probably going to go to bills," she said. "That makes for a very hard month. A person has to eat."
Across the country employers of all sizes are making contingency plans for a hard-hitting flu season.
Some business owners are cross-training employees to fill in for absent colleagues. Others are relaxing sick leave policies that require a doctor's note. (Many doctors' offices are advising swine flu patients to stay away unless their symptoms are severe to prevent overwhelming the health care system. )
Some corporations are heeding advice from the U.S. Centers for Disease Control and Prevention. Among their tips: moving desks farther apart, creating more shifts to have fewer people on duty at a time and reducing employee travel.
But that advice doesn't do much for many companies — particularly small businesses or those in the service industry where sick leave is almost unheard of or too costly for owners to afford.
"We don't have a real good contingency plan in place right now," said Gordon Weitzel, owner of Dayton's Chicken & Seafood in Salisbury, Md. His staff of 36 does not have sick leave.
"I've got some servers who cook, and I've got a lot of different people I can flip-flop. But it most certainly would be a hardship if 20 or 25 percent of my staff had swine flu" and stayed home, he said.
About a third of the nation's workers don't have paid sick leave, according to the U.S. Department of Labor. But even some workers who do don't take it because they fear retribution from their bosses if they don't show up.
The problem can be worse for parents who worry not just about their own health, but their children's. After all, a sick kid who got the flu from Mom or Dad can mean even more time off the job.
Kevin Huigens, 52, knows calling in sick means bringing home a smaller paycheck, or possibly none at all. As a technology contractor in suburban Chicago, his job doesn't come with sick leave or vacation time.
So what will he do if he gets sick this winter?
"If I'm well enough to sit up in bed with a laptop, I can still work," he said. "I can work from home somehow, some way. It may not even be a full eight hours, but I can get a few hours a day."
Even that might not be doable for some particularly ill patients.
Last year, Chicago real estate agent Jen Sanders was felled for five days by the seasonal flu after forgoing a flu shot for the first time in a decade. Stuck at home, she had to call other real estate agents to attend everything from home inspections to showing listings to potential buyers so she wouldn't risk losing her commission.
"It's horrible when you feel so crappy and you realize that you are losing money at the same time," she said.
This year, she made sure to get a flu shot. She'll also continue her strategy of keeping her gloves on during the height of the winter flu season when she's shaking hands.
"Every time I do a showing, I greet people," the 35-year-old said. "I try to do what I can without making other people feel awkward."