Thinking ahead may also involve purchasing travel insurance, particularly plans that cover trip cancellation, in case an incident arises between the time of booking and the time of travel, or trip interruption, when something occurs during travel.

“You need to do the research on the insurance plan to make sure the insurance plan you buy covers a violent act or State Department warning, or that an incident doesn’t void your plan,” said Jason Clampet, co-founder and editor in chief of the travel news site Skift.

Travelers interested in learning to identify threats and mitigate risks from the pros can take a new online course that covers awareness and emergency response from AKE International, a global security firm that specializes in corporate travel and protecting high-net-worth individuals (the course costs about $65).

Security experts and travel professionals advise being prepared when traveling abroad, including packing to maintain a low profile by leaving behind any flashy jewelry, short shorts and Yankees baseball caps. Experts also stress avoiding gatherings and large crowds.

“If there’s a demonstration, don’t watch and hang out,” Mr. Berkeley said. “Go the other way.”

Additionally, travelers should practice basic awareness, which means paying attention to what’s happening as you step out of a hotel, restaurant or train station.

“The biggest thing we find is that people are completely unaware not only of issues that occur in that destination, but unaware of what’s going on around them in public because they’re looking at their phone,” Mr. Hagon said.

FoneTrac, a newly updated app from GlobalSecur (part of the Incident Management Group), delivers security alerts in the event of an emergency and monitors users’ locations by asking them to check in on a regular schedule with the tap of a button. A panic button summons immediate assistance. The basic service costs $12 a month, with more expensive options that include emergency medical support and evacuation coverage.