Ah, summer. The time for swimming, barbecue and general fun in the sun. What summer is not time for is sniffling, sneezing, congestion, aches, pains, sore throats and fevers.
Yet summer colds are still a thing that happen, and they somehow seem far worse than a cold you get in the winter. Are these colds really worse, or do they just feel that way because we don't think of summer as a cold season?
Enter the enterovirus
It's a little silly of us to think colds are just wintertime occurrences. There are more than 200 different viruses that can cause the common cold, according to the U.S. Centers for Disease Control and Prevention. Still, the symptoms remain mostly the same — sniffling, sneezing, coughing and sore throat — regardless of the particular virus you catch.
Given the odds, it's a little surprising we don't get colds in the summer more often. The reason the odds are in our favor, at least when it comes to summer colds, is that viruses have seasons. So just like the changing of the leaves and the blossoming of flowers, cold viruses change with the seasons. Rhinoviruses, which are perhaps the cold-causing viruses you're most familiar with, thrive during the late fall and winter but don't do so well in the heat of the summer. There are a lot of rhinoviruses out there, too. In fact, we've identified 160 different rhinoviruses.
Summer is the season for the enterovirus. Unlike the rhinovirus' sizable cold-causing population, there are around 70 known enteroviruses that can cause infections in humans. If you've heard of the enterovirus, it's probably been in conjunction with polio, which it can also cause. We have a vaccine against polio, so we can guard against the enteroviruses that result in that disease. There are still more than 60 types of non-polio-causing enteroviruses, however, and many of those can bring about the common cold.
The enterovirus is one reason why summer colds tend to feel worse than their wintry brethren. In addition to the standard cold symptoms, some less common enteroviruses can cause diarrhea, pink eye or rashes. Furthermore, enteroviruses can linger longer, both during the actual cold and then after you've somewhat recovered.
"Winter cold viruses tend to make you feel really sick, and then you get over it," Bruce Hirsch, attending physician for infectious diseases at North Shore University Hospital in Manhasset, New York, told Live Science in 2011. "Summer colds just seem to lurk in the background ... and just go on and on and on."
Another reason the summer cold feels like the pits is just the mental aspect of it. We simply don't want to be sick during the summer. Sure, there's all the fun you're missing out on because you're indoors, but does anyone really want a fever during a heat wave?
"We feel a summer cold is worse than a winter cold, as we do not expect to suffer from what most view as a winter ailment when it is sunny and warm in the summer," Ronald Eccles, director of the Common Cold Center at the University of Cardiff in Wales, told U.S. News and World Report in 2015. "So there is a psychological aspect to the perceived severity of the cold and its impact on our lifestyle."
The same prescription in summer as in winter
Regrettably, the enterovirus and the rhinovirus have something else in common: There's no real treatment. Standard over-the-counter cold medication will help to alleviate symptoms, along with cough drops and saline sprays. Getting plenty of rest indoors, staying hydrated and eating a balanced diet will also help, just like it does with a wintertime cold. And antibiotics aren't going to help with a cold caused by a virus, so don't bother asking your doctor for any.
Although it keeps you cool, running the air conditioner may hurt more than it helps. That cold air can dry out your sinus passages, and while mucus is annoying sometimes, it also helps by grabbing germs before they get too far into your system. If air conditioning has depleted your mucus, there's less protection against germs. Plus, since air conditioners simply recirculate the same air over and over again, you get a system where the viruses just keep getting pushed around in potentially constricted and dried-out nasal passages.
Prevention, naturally, is key. Washing your hands and avoiding sick people can help you avoid getting sick yourself. An enterovirus can spread through coughing, sneezing and fecal-to-oral contact, and that means any infected surface can transmit the virus.
So just because it's summer, don't let your guard down about the common cold. You don't want to spend your vacation sick in bed, after all.