I always get ill when busy or travelling. How do I prepare?

Many people get ill during the year-end rush or after frequent travel because several things happen at once: short sleep builds up, you spend time in crowds, meals become irregular, and your body has to adjust to new time zones. What you can do is prepare in stages, before the busy period, on the way and on arrival, starting with 7 hours of sleep or more, frequent handwashing, enough to drink, and using daylight to reset your sleep.

Why do I always get ill when I'm busy or travelling a lot?

The end of the year brings deadlines to close, parties, and long holidays when many people travel home or go away. Your body faces several pressures at the same time.

Short sleep adds up without you noticing

Year-end deadlines, early meetings, dawn flights and late parties chip away at sleep until it becomes ongoing short sleep. The US CDC recommends 7 hours or more for adults aged 18 to 60. For research on short sleep and getting ill, see Weather keeps changing and I get ill easily. What can I do?

Time in crowds

Airports, bus and train stations, public transport, meeting rooms and year-end parties all put many people close together in enclosed spaces. The CDC lists regular handwashing, cleaning commonly touched surfaces, and taking steps for cleaner air where people live and work as the basics of reducing the spread of germs that make people ill.

Dry air on planes

The CDC says aircraft cabin air is usually dry, at around 10 to 20% humidity, which can dry out the lining of your nose and throat. Cabin air is refreshed 20 to 30 times an hour, far more than in most office buildings, and recirculated air passes through HEPA filters that capture 99.97% of particles. Even so, sitting close to other passengers raises the chance of germs spreading from person to person through the air before it is cleared.

Irregular meals and more alcohol

When work piles up, people skip meals or eat late, and when travelling they eat around flight times and appointments. Year-end parties also mean drinking more often than usual. The CDC's advice for business travellers is that, to lessen the health effects of stress, you should eat healthy meals, exercise regularly and avoid alcohol.

Your body clock has to catch up

After flying across time zones, your body clock stays anchored to home time for several days. The CDC notes that during this time you may have disturbed sleep, daytime sleepiness, slower thinking, a general sense of feeling unwell and an upset stomach. On average, the body adjusts by about 1.5 hours a day after flying west and about 1 hour a day after flying east.

I get ill every year-end busy season. How should I prepare my body?

Start before the busy period actually arrives, because once work is overflowing it is hard to find time to change habits.

Set your sleep before the peak

• Plan for 7 hours of sleep or more, counting back from the time you need to get up.
• Go to bed and get up at the same time every day, including days off.
• Turn off electronic devices at least 30 minutes before bed.
• Avoid large meals and alcohol before bed, and caffeine in the afternoon or evening.

These are all CDC sleep recommendations. If you genuinely have to work late one night, treat it as an exception and return to your usual times as soon as you can.

Plan meals and parties

• Prepare quick meals in advance so you do not skip meals on days of back-to-back meetings.
• If you have several parties, choose some where you do not drink, or drink less.
• Get up and move during the day, even for short spells.

Prepare early if you have a trip abroad

The CDC advises booking an appointment with your doctor or a travel medicine specialist at least a month before you leave, to get advice, medicines and vaccines suited to your destination. Also check whether your health insurance covers medical care abroad, because many plans do not.

I travel a lot for work and holidays and always end up ill. What can I do?

Split your care into three stages: before you leave, on the way, and on arrival.

Before you leave

The CDC suggests shifting your sleep by 1 hour a day over the 2 to 3 days before you travel. If you are flying east, for example to Japan or Korea, go to bed earlier. If you are flying west, for example to Europe, go to bed later.

The CDC also recommends packing a travel health kit: your prescription and over-the-counter medicines (enough for the whole trip, plus a little extra), first aid supplies, an alcohol-based hand sanitiser, sunscreen of SPF 15 or higher, and your health insurance card.

On the way

• Wash your hands thoroughly and often, or use a hand sanitiser with at least 60% alcohol when soap and water are not available, especially after touching handrails and armrests and before eating.
• In crowded places such as airports and on board, the CDC says a high-quality, well-fitting mask adds another layer of protection against the spread of germs.
• Drink enough. The CDC notes that dehydration can make the effects of changing time zones worse, and that both alcohol and caffeine can dehydrate you.
• Cabin air is dry, so sip water regularly rather than drinking a lot at once.

On arrival

• Get light that matches local time. The CDC explains that bright morning light moves your body clock earlier and evening light moves it later, so after flying east get out in the morning light, and after flying west get light in the evening.
• If you are sleepy in the day, take a short nap of 20 to 30 minutes. Longer naps can make it harder to sleep at night.
• The CDC says food that is fully cooked and served hot, as well as dry and packaged foods, is generally the lower-risk choice, as are bottled, canned and hot drinks.
• Apply sunscreen of SPF 15 or higher when you are out in the sun.

I'm already ill. Should I go to work or keep travelling?

If you are already ill, the CDC advises staying home and away from others, and says people with a cough, sneezing or a fever should put off flying until they are no longer likely to pass it on.

If you really have to go

• Ask your manager or team about joining meetings online instead of in person.
• If you still have to be around others, wear a mask, cover coughs and sneezes, and wash your hands often.
• Do not share cups or towels with others.

Building some slack into your year-end schedule makes it possible to actually rest when you feel unwell, instead of pushing on until it drags out.

When should I see a doctor?

The CDC advises that if you travelled and feel ill, especially with a fever, you should talk to a doctor and tell them where you have recently been. The UK's NHS says most people begin to feel better in about 1 to 2 weeks, and advises seeing a doctor if:

• you have a high temperature for more than 3 days, or a very high temperature or you feel hot, cold or shivery
• your symptoms do not get better after 10 days
• you have a cough for more than 3 weeks
• you feel short of breath or have chest pain
• you have an ongoing health condition that needs regular care
• you are worried about a child's symptoms

If getting ill has become a regular part of every busy season, it is also worth talking to a doctor to look into the cause together.