How to quarantine correctly if you've been exposed to the coronavirus

• Quarantine is for people who've been exposed to a contagious disease, like the coronavirus, but who are not yet sick themselves.
• Quarantine for the coronavirus lasts 14 days from a person's last known exposure.
• During that time, it's important to stay away from people who haven't had the exact same exposure.
• A quarantine expert shared his tips for how to do quarantine right, including when it's safest to relax your precautions, and how to go outside during a quarantine.

A quarantine for the coronavirus lasts 14 days.

During that time, people who've been exposed to others who have COVID-19, the disease caused by the virus, are isolated from people who haven't had that same exposure to stop the virus from being passed along.

If 14 days away from others sounds like a lot, consider this: Some of the very first quarantines, on merchant ships arriving in Venice some 700 years ago, were almost three times that length. According to the Centers for Disease Control and Prevention, ships arriving "from infected ports" were required to sit at anchor for quaranta giorni (40 days) in an effort to prevent festering plagues from elsewhere being brought into town. Thus, quarantining was born.

The isolation measure is still in use today because when it's done well, it works almost perfectly at keeping diseases, like the coronavirus, away from new people and places.

"If I was asked for one thing that could improve that might change the game here, that is: making sure that each and every contact of a confirmed case is in quarantine for the appropriate period of time, so as to break chains of transmission," World Health Organization executive director of health emergencies Dr. Mike Ryan said earlier this month, as the number of new cases being diagnosed across the US and Europe soared.

Insider has compiled below answers to the most pressing questions about successful quarantining strategies in 2020 with the help of a former CDC officer, who says he used to put people in quarantine "all the time."

Do you have to quarantine alone? Not necessarily.

Quarantine is for people who've been exposed to a sick person, but who are not (or at least not yet) sick themselves. So a quarantine does not necessarily have to be a solo endeavor.

"Quarantine could be a party," Dr. Rishi Desai, chief medical officer at Osmosis, and a former Epidemic Intelligence Service officer at the CDC told Insider. "It doesn't mean you have to be alone, it means you have to be away from people that haven't had that exposure. If others have had the exact same exposure you had, then you can stay with those people."

The first NASA astronauts to land on the moon did this, quarantining for 21 days together after they returned to Earth to ensure they didn't bring any "lunar contagions" back with them.

However, if during quarantine, you develop tell-tale symptoms of the coronavirus, that's when you have to go it alone.

"If you're sick, that's where you're isolated," Desai said.

If someone in a quarantine "party" does get the virus, they need to be taken out of the group and isolated completely, ideally in a space with their own bedroom and bathroom.

If you can't be in your own solo unit, take care to rotate when you use the bathroom, and generally avoid being in the same space at the same time as other roommates.

"When you have to be in a shared space, like a bathroom or a living room ... you make sure that time-wise, you keep it so that you're not both in that same space at the same time," Desai said. "As much as you can, you wipe down surfaces."

Adding lots of space and time into the equation helps prevent virus transmission to new people.

"For every minute that passes, the amount of virus in the air diminishes," Desai said.

Which are the most dangerous days of a quarantine? Typically, days 5, 6, and 7 are the riskiest time.

While in quarantine, you ideally shouldn't go out to run any errands.

"Quarantining at home for 14 days; that means not going to work, it means not going to the grocery store, it means not socializing with friends, it means not having people over at your home," WHO technical lead for COVID-19 Maria Van Kerkhove told reporters earlier this month.

But if you must go out, it's best to make your excursion as quick and as safe as possible.

First, avoid going out altogether on the days you're most likely to be infectious.

"Day five, six, seven, those are your high risk days," Desai said. "Usually if you were to develop symptoms, it's going to be between, let's say, two and 12 days [after exposure]."

That's because the virus generally incubates for a few days before you get sick.

The moment after being exposed to a sick person, you are not going to be contagious to others. But two days later, you could very well be capable of passing the virus along to someone else.

This contagious period for COVID-19 often starts before you feel sick, meaning you could be facilitating the spread of a deadly disease that can easily kill vulnerable people before you ever know it.

What about running errands during quarantine? If you must, suit up and make it snappy. But first, make sure it's necessary.

Before venturing out in public during quarantine, check to make sure that you really can't avoid going out. Maybe your local health department is facilitating food drop offs, or offering quarantine hotel rooms. There might be nearby contactless grocery delivery services that allow delivery people to leave bags of food at your door.

Assuming a worst-case scenario where there is no one around to help, and you desperately need to get food or supplies, Desai says the key is making any essential shopping trip snappy. Suit up well and avoid touching your face while you're out.

"Completely mask up, maybe wear gloves, just completely cover yourself," he said. "You wash your hands before you go, you wash your hands when you come home, and that's what you do. And you minimize the amount of time you spend at the grocery store. Because again, every minute you're there, every minute you're breathing, you're contaminating."

Is a trip out to the park to visit with a friend during quarantine OK? Yes, as long as you're both careful.

Finally, if you want to get out into some fresh air while in quarantine, Desai says you should go for it. Just keep a safe, 10 foot distance from others while you're out, don't touch anything, and wear your mask at all times. He even endorses meeting a friend in the park during your quarantine, as long as you keep a safe distance from them and you're not feeling sick.

"Most people are going to need to do that to stay mentally well," he said. "You can't just not see humans."

Desai says that just by reading this article, you're probably on the right track.

"If you're already thinking through how to do it so you're doing it right, you're probably doing a good job," he said. "It's the people that are just blowing caution to the wind who are the ones that are causing these spreader events."