Spring is a time to celebrate blooming flowers — and curse seasonal allergies. You may enjoy later sunsets and struggle with darker mornings.

Spring also welcomes the first ambitious trip of the year for many of us before we can bid adieu to flu season, which was particularly bad this year. I recently got hit with the paradoxical case of stuffy-yet-runny-nose halfway through a ski trip.

As airports brace for a surge in passengers, “there’s actually a pretty good chance that people traveling may get sick,” said Benjamin Barlow, the chief medical officer for American Family Care and a former senior White House physician.

It doesn’t help that we’ve “relaxed a little bit” when it comes to illness awareness, Barlow said. Many of us are no longer hypervigilant when it comes to hand-washing, mask-wearing, crowd distancing or staying up-to-date on vaccines.

If you’d like to avoid a mid-trip bout of illness, you’ll want to refocus all of those efforts. (Yes, the masking, too, even if it does feel very 2020 to some.)

“Wearing a face mask in high-traffic areas like TSA checkpoints, boarding and deplaning is another simple yet effective step,” said Mark Gendreau, a physician and the chief medical officer for several hospitals in the Beth Israel Lahey Health system in Massachusetts.

You’ll also want to remember all of the other healthy living basics, including a well-rounded diet, getting plenty of rest and exercise, and going easy on the alcohol. To beef up your immune system along the way, I asked doctors to weigh in on what else you can pack.

Hand sanitizer

One of the main ways we get sick is by touching dirty surfaces, then touching our nose or mouth. Between hitting the airport bathroom and food court, Barlow said, we can touch dozens of surfaces without realizing.

We can fight this issue by washing our hands regularly, but also by packing (and regularly using) hand sanitizer.

“It makes a big difference when you’re traveling,” Barlow said.

Ali A. Khan, a gastroenterologist with Gastro Health in Fairfax, Virginia, also recommends bringing along disinfecting wipes to clean off surfaces like Amtrak armrests or airplane tray tables.

“It’s a low-hanging fruit way to get rid of some germs,” he said.

Vitamin C and zinc

Barlow said evidence is mixed on how helpful supplements can be for preventing or treating colds.

“It’s always a tough answer because it depends on someone’s baseline diet,” he said.

If you’re eating a healthy diet with lots of fruits and vegetables, then supplements “probably don’t do you much good,” he said. “However, if you’re eating fast food every day and not getting appropriate nutrients, then they work great.”

A water bottle

Robert Biernbaum, the chief medical officer at WellNow Urgent Care, has an easy directive for staying healthy: “Stay hydrated.”

How hydrated? Barlow tells patients to watch their urine and adjust accordingly. If your pee is looking dark, drink more water. If it’s completely clear and you’re running to the bathroom every hour, you may be drinking too much.

“Your body does a good job of regulating it for you,” he said.

Nasal sprays

Katrina Johnson, an internal medicine physician at Ohio State University’s Wexner Medical Center, travels with a go-bag of first-aid basics such as Benadryl and bandages. For allergies and congestion — which she said is a common issue for people after flights — she brings a saline rinse. “That’s an easy one where you can just quickly cleanse the nasal passages once you get to where you’re going,” she said.

Johnson also brings medicine like Flonase (to reduce nasal inflammation) and Afrin (a decongestant that you should use for only about three days, as doing so for any longer can lead to “rebound congestion,” she said).

Gendreau noted that saline rinses such as neti pots can give you relief from congestion and can theoretically reduce viral load, but there aren’t rigorous studies confirming their efficacy in preventing colds or the flu.

Sleep essentials

Travel often disrupts our sleep routines — and good sleep is critical for your overall health.

“Our body recovers when we sleep, so if you’re not sleeping, you’re losing that recovery period,” Barlow said, adding that sleep deprivation can throw your hormones and immune system out of whack.

You can improve your travel sleep by packing items such as a light-blocking eye mask; a white noise machine; and light-blocking stickers to put over blinking routers or cable boxes.

Family medicine physician Bernadette Anderson, the author of “Fulfilled: 52 Prescriptions for Healing, Health, and Happiness,” said a calming tea can help you relieve stress and create a relaxing nighttime ritual. As it steeps, practice a short meditation to help yourself unwind. To best support your body’s natural defenses, Anderson said to aim for seven to nine hours of sleep.