First rule: Be adaptable and have access to many platforms, apps, methods, and virtual and physical backup options.

—Decide with family, friends, and colleagues where you will rendezvous if communications are interrupted. Include both a location and an agreed upon window of time.

—Have paper and pen on hand to leave notes as needed.

—Have a watch or clock not connected to the internet.

—Download essential material including maps on your phone.

—Have a physical map of the city and the region, plus a compass.

—Have extra minutes from your mobile operator available

What Apps to Use—and What to Avoid

—For private communication, the Signal and Wickerme apps are the most secure and reliable. Sometimes, the more popular Signal can get overloaded, so it is not a bad idea to use Wickerme as a backup. It is safer to use these apps instead of Telegram, Viber, What’s App, Messenger, regular texts, etc.

—Telegram, which is popular in Ukraine, is not reliable for secure person-to-person communications. You cannot expect privacy, and should migrate to Signal or Wickerme. Only use Telegram to follow news and information channels you have reason to trust; in this regard, it is better than Facebook and Instagram to share quick info to lots of people.

—Even if internet or cell service is not working, FireChat, if widely downloaded by people in the city, enables users to relay messages between phones nine meters apart (sometimes more). Note: FireChat is totally insecure; it is simply a means to communicate when all other options fail.

—Keep devices charged; have battery backups ready.

By Joe Lindsley