For those of us in good health, the flu feels like more of an annoyance than a threat—a few days of being stuffed up, some aches and pains, maybe a fever. But for the old, the young and the immune-compromised, the flu can be deadly. Flu-related mortality ebbs and flows from year to year, bouncing around from 1.4 to up to 16.7 deaths per 100,000 people per year in the United States, according to a 2010 CDC report. This lingering threat, taken in context, makes a new study out of McMaster University even more troubling.

In their report, the scientists tried to figure out the effect of fever-fighting medications like aspirin or ibuprofen on flu transmission.

Previous experimental research, says Science magazine, had shown that “lowering your body temperature may make the virus replicate faster and increase the risk that you transmit it to others.” Your body turns up the heat to try to cook the flu virus out. By stymieing the fever with medication, you're also making it easier on the virus. Having more virus flowing through your system, the scientists suggest, makes you more likely to transmit it to those you meet.

The scientists extrapolated from this potential for a higher transmission rate to calculate the effect on the wider population, says the CBC.

"We put together a chain — how many people have influenza, how many of them take these anti-fever drugs, how much does that increase the amount of virus they give off, how much does that increase the chance that they’re going to affect somebody else, how much does that increase the overall size of the seasonal flu epidemic," said Ben Bolker, professor of math and biology. ...After crunching numbers, the researchers realized that avoiding medications with ibuprofen, acetaminophen and acetylsalicylic acid and just staying home could save many lives. Their research estimates as many as 1,000 lives across North America each year could be saved.”

The work is still preliminary, says Science, and the researchers tried to keep their calculations conservative: “they didn't even include the effect that after an aspirin, people may be more likely to go out and meet people, increasing chances of spreading disease.”

Taking anti-fever medications may make you feel less sickly, but they may also make you more contagious. The best bet then, it seems, is to pop the pills—or skip them altogether—and just stay in bed.