Despite its name, the common cold isn’t caused or spread by cold weather. In fact, colds are caused by over 200 viruses, the most common of which are rhinovirus. In fact, a Canadian study found that rhinovirus accounted for 24%-52% of clinical cases.

So how contagious are these viruses, and how do they spread?

Well, we know that the incubation period, or time between becoming infected with the virus and developing symptoms, is about one to three days. The infectious period, or time that the virus is contagious, actually starts before you even suspect that you might be sick. About one day before you start to show symptoms, you begin to be contagious, and this period continues for the first five days of the illness.

When considering how contagious someone might be, it’s important to not only consider the timeline of a cold but the severity of your symptoms. This is because the cold is transmitted through tiny droplets of infected moisture that are spread when you cough, sneeze or even breathe. The more frequently you’re coughing and sneezing, the more infected droplets you’ll be spreading.

For example, it’s estimated that a sneeze can spread up to eight metres. It’s not just the visible fluids that are airborne, but clouds of gas that carry tiny infectious droplets. Because they’re so small, these droplets not only stay in the air for a longer period, taking time to settle, but they can also be breathed in by other people.

Unfortunately, the damage isn’t done once the droplets eventually settle. They can land on any surface and stay active for hours on end. These surfaces are then touched by other people, who spread the virus to other things they touch, including their face. When the infectious droplets are spread to mucous membranes by touching the eyes, nose, or mouth, the person becomes infected.

This principle was best illustrated by the University of Arizona during a study in 2014, where they gave one person in an office a droplet containing an artificial virus designed to mimic the viruses that cause cold, flu, and stomach bug. The employees were instructed to go about their day as usual. At the end of the day, they found that 50 per cent of surfaces and employees were infected by at least one of the viruses. The researchers calculated that the employees faced a 40 to 90 per cent chance of infection with one of the three viruses.

The study showed just how quickly these contagious viruses were spread — but it’s not all bad news.

They then repeated the study, but this time introduced interventions like free tissues, disinfectant wipes, and a bottle of hand sanitizer, as well as encouraging staff to wash their hands. These interventions dropped the risk of infection to below 10 per cent.

The takeaway? If you’re sick, going into a confined space with other people, such as an office, school or care facility can very quickly spread the virus. For this reason, it’s a good idea to stay home if you’re feeling unwell — not only to recover but also to avoid spreading the virus to others. Your Capital Chemist pharmacist may be able to issue with a workplace leave certificate or carer’s leave certificate if you need to stay home.

If you’re around other people, you can reduce your chances of spreading the cold by using tissues when you cough or sneeze, and throwing them in the bin immediately after you’ve used them. If a cough or sneeze comes on before you have a chance to get a tissue, use the inside of your elbow to cover your mouth and nose. Avoid using your hands, as you can easily spread the virus through touching surfaces or other people.

It’s also very important to regularly wash your hands with soap for at least 20 seconds, especially before and after eating or using the toilet. Hand sanitizer is also a good option for carrying with you on the go or even storing a bottle on your desk. It’s also a smart idea to habitually use disinfectant wipes to regularly wipe down surfaces, especially those which are regularly touched such as handles on appliances, cupboard and doors, phones, and keyboards.

Unfortunately, if you do get a cold, it can’t be cured. However, there are treatments available to relieve some of the unpleasant symptoms. Speak to your local Capital Chemist pharmacist to find out which treatments are best for you.