Got a cold? Sweat it out, or don't

I can never remember what to do when I have a cold.

Starve it? Feed it? Cool bath or warm sauna?

I’ve tried Vicks on my feet, chicken broth, and even crushed garlic in a glass of milk (I was trapped and held hostage by my friend’s grandmother).

Here’s what worked the best: acting pitiful so my husband kept the kids away.

Granted, this only worked once.

“Sweating it out” is not something I’ve tried because heat makes me grumpy. But it is common cold-busting advice, so I was asked to write a blog about whether heat can cure a cold or if it is just … a bunch of hot air. I found out “sweat it out” means different things to different people, ranging from intense workouts to eating hot peppers. Aside from curries and jalapenos, however, the “sweat it out” methodology boils (pardon my pun) down to two categories: actual sweating or inhaling warm, moist air.

Actual Sweating
Sweat-producing exercise MAY temporarily relieve symptoms because of the feel-good endorphins it releases but it is unlikely to cure a cold. The purpose of sweat is to cool your body down, which is why high fevers cause perspiration. Creating sweat through exercise temporarily increases your body temperature as a fever would, but it is not enough to reduce the amount of cold virus in your body.

If you feel up to working out, go for it; but don’t force yourself to maintain your normal routine. If you have fever or a severe cough or wheezing, ask your healthcare provider if exercise is a good idea. It may be best to take a few days off.

There’s talk that sweat will rid your body of toxins. There are some studies that detected small amounts of some toxins, but the kidneys and liver filter out substantially more toxins than those sweat glands could ever hope for. There is no evidence that “sweating it out” improves health. In fact, for some people it could be very dangerous. Sweat is primarily water with some small amounts of electrolytes; activities that cause sweating require fluid replacement otherwise you will become dehydrated which will complicate a cold. Worse, forcing your body to sweat can make your kidneys hold on to all the water they can. This sounds OK until you remember that the water that goes to the kidneys is full of toxins. If the kidneys are forced to conserve water, they will do it by not filtering out the toxins.

Inhaling Warm Steam
Breathing in warm steam can temporarily relieve congestion by loosening mucus, but there is not a lot of evidence to support it. In fact, there are accounts of severe illness and even death from overheating in sweat lodges or saunas. Heat stroke is a real thing, my friends. The Cochrane Database of Systematic Reviews are the highest standard in evidence-based healthcare; according to them, breathing in hot air does not produce a cure or even reduce the amount of virus in your body. If a steamy shower or humidifier relieves your symptoms, go for it (unless your provider advises differently). Just be sure to clean your humidifier according to manufacturer instructions because there are bacteria that love to set up camp in wet areas. The last thing you want is your humidifier to release other germs into the air!

So here’s the rub … exercise and humidity make temporarily make you feel better by relieving congestion and giving you a boost of endorphins. They won’t cure you or shorten the illness, though. More importantly, if not done with care, you could end up worse off than when you started. Steam burns, feeling lightheaded, and dehydration are a few of the things you will need to be careful of.

Hey, but what about the garlic milk?
In case you are tempted (or held hostage by someone’s grandma), the garlic milk did not work. Chicken soup can be good for you but it’s not a cure. Vicks? Well, see below.

Remember that tidbit about Vicks on the feet?
Neuroscientists are smart. Really smart. These aren’t the kind of folks that are persuaded by old wives’ tales and other medicinal folklore. They are, however, the kind of folks that will research and test ideas. Two neuroscientists, one the winner of a Nobel Prize, discovered preventing muscle cramps is less about the muscle and more about the nerves. Treating the misfiring nerve will stop the cramps, or so the story goes.

I have known runners who drink pickle juice or concoctions involving curry or hot sauce to stop muscle cramps. They swear by it despite being accused of quackery. Well, now there is evidence suggesting that this may actually work, but not for the reasons we assumed. Pickle juice was believed to provide fluid and electrolytes. I’m not sure what curry does, my friends joked that maybe it just made the body focus on something more important … a burning palate. It turns out that maybe the stimulation of the nerves in the mouth, esophagus and stomach is actually calming overstimulated nerves in other parts of the body.

Neuroscientists are smart but not smart enough to master all of neurobiology. Our neurological system is incredibly complex. There is still much we don’t know, especially on how sensory nerves in one area can affect how our body functions in another. What these two neuroscientists are trying to show is that stimulation of nerves in the mouth affected the spinal column which overwhelmed the nerves that were misfiring and causing cramps. Those nerves responded by chilling out (not a scientific term) and the muscles were grateful and stopped cramping.

How does this relate to menthol, camphor and eucalyptus oil on the feet? One pharmacologist is speculating that if we misunderstood muscle cramps, have we also misunderstood coughs? In other words, we assumed muscle cramps were about the muscle so we treated the muscle and dismissed those that swore tonic water and spoonfuls of mustard at night stopped their leg cramps. What if coughs can be reduced by overstimulating some nerves, and those nerves happen to be in the feet? That could explain why slathering the feet with mentholated ointments is the home remedy people swear by.

Mind you, this is all speculation. If you have a cough, see your healthcare provider. There is no evidence to suggest that mentholated ointments are a treatment or cure for coughs, and the science is young and limited regarding whether spicy foods stop muscle cramps.

The verdict: Pickle juice and mentholated feet remain urban legend, with a caveat. The research is sparse and low-quality, but interesting and I expect some better studies will start trickling in.

In the meantime, stay hydrated, eat well, and see your healthcare provider for coughs, cramps, and other concerns.

Important note: Every reputable, or mostly reputable, place I looked emphasized that Vicks and similar products should not be used at all on children under the age of two.

Kate Craig, BSN, RN, is the Administrative Director of Nursing at The Legacy Living and Rehabilitation Center in Gillette, Wyoming.