What should you know about jet lag day?

Your body clock may still be following the time zone you left. That mismatch can produce daytime sleepiness when you need to be awake, difficulty sleeping at the local night, poor focus, irritability, and headache. Caffeine may temporarily improve alertness but does not reset the body clock, and taking it late can delay sleep. The first local day is also affected by travel fatigue, a cramped journey, and disrupted meals.

Get outside in daylight at a time that fits your travel direction and planned bedtime; ask a clinician or travel health service for personalised timing if the journey crosses several zones. Walk gently and keep meals close to local breakfast, lunch, and dinner. If you nap, keep it brief and early enough to protect nighttime sleep. Drink water and avoid using alcohol as a sleep aid. Keep demanding tasks, swimming alone, and driving for times when your alertness is reliable.

Speak with a clinician if daytime sleepiness remains strong after your sleep pattern has had a chance to settle, causes near-misses while driving, or occurs without recent travel. Urgent assessment is needed for sudden confusion, collapse, chest pain, breathing difficulty, a severe new headache, or one-sided weakness. Persistent difficulty sleeping may need assessment for insomnia or another condition.

Ask when daylight, exercise, caffeine, and naps are most helpful for your route. Tell the clinician about your arrival time, usual sleep pattern, medicines, pregnancy, and any condition that makes fatigue or dehydration more concerning.