This pales in comparison to the tragedy unfolding within Ukraine itself, but travelers should be aware of potential side-effects of the conflict impacting air travel. There have been some already, and we can probably expect more as things escalate and all parties settle in for a long conflict.
The Russians are attacking airports in Ukraine; some may still be open, but it's reasonable to expect air travel to/from the country to become increasingly challenging, eventually impossible. Not a surprise when there are combat air missions taking place.
Flying over Ukraine has always had some higher potential for Bad Things happening (Russian separatists have shot down airliners, commercial flights have effectively been hijacked by pro-Russian allies to snatch opposition figures). Now that a full-blown war has broken out, most airlines are going to steer clear of Ukrainian airspace, maybe for a long time. If nothing else, some flights may get longer as aircraft fly around the region to avoid potential dangers.
The UK has already banned the Aeroflot (the Russian national airline) from their airspace. The Russians have reciprocated. There will probably be more such bans and retaliations.
If the airspace bans do continue and spread, this has the potential to impact a lot of worldwide air service: many long-haul flights (headed to destinations nowhere near Russia) cross Russian airspace.
Then there's the potential for cyber-warfare impacting many systems. So far, it seems the worst fears of potential widespread Russian cyber-attacks (and rumored US retaliation) have not materialized. Let's hope it stays that way. If that starts and escalates, it has the potential to mess with many things we use every day, even when we are not traveling.