Imagine this scenario: you’re packing up your last few things before leaving on vacation, and you feel the dreaded sniffles coming on. What do you do? Since it’s basically everyone’s worst nightmare to have to cancel vacation for any reason at all, many people choose to ignore their symptoms and travel while ill in an attempt to salvage their trip. Others decide to cancel, since vacationing while being sick isn’t the best experience either. If you’re on the fence about jetting off to paradise while under the weather, check out these tips and guidelines.

1.) Assess your illness

Contagion is one of the biggest worries when it comes to traveling while sick. Ailments such as migraines, motion sickness, or asthma flare-ups aren’t a cause for concern since they usually clear up quickly and can’t be passed on to your fellow travelers. Other sicknesses, such as colds, sore throats, and sinus infections can be trickier to determine. If you have strep throat, a sinus, upper respiratory or ear infection, you should probably postpone your trip. This is especially the case if you haven’t been on antibiotics for at least 24 hours. While you may think you’re feeling well enough to travel, CDC may not agree. The CDC has a guideline of symptoms that should not be ignored. You should cancel your trip if you have a fever over 100.6 degrees Fahrenheit. You should also cancel if you have flu-like symptoms that include the following: chills, nausea, vomiting, diarrhea or body aches. These are all highly contagious symptoms that could potentially infect thousands of other travelers, so please don’t travel if you are showing these symptoms.

2.) If you’re too sick to travel, call your doctor first

If you’ve determined that you’re going to cancel your trip, and you’re within 24 hours of your flight, call your doctor. You should have documentation of your illness since you’re staying home. Some airlines will waive your change fees for last-minute cancellations if you have proof from a doctor that you really are too sick to travel.

3.) Call the airline

Dig up your fare rules from your booking confirmation and read up on the airline’s cancellation policy. This way you’ll be thoroughly prepared to call the airline and explain your situation. Airlines don’t want you flying while ill any more than you do, so they can often be accommodating. However, be aware that most domestic airlines don’t allow cancellations for illness without some kind of penalty. Usually, the cheapest option is to postpone your flight a few days if you’re able to rearrange your schedule. If you can’t immediately reschedule, a vast majority of airlines will provide a credit towards future travel, so your trip isn’t just money down the drain. If you run into trouble and you have travel insurance, now is the time to see what is covered under your policy. Contact customer service to see if they can pull any strings or help cover any losses you’ll incur from the last-minute cancellation.

Being sick is never fun, but traveling sick not only slows down your ability to heal but it also exposes many fellow passengers to contagious virus or bacteria during a period where immune systems may be weaker than normal.