Other people have amazing reasons not to come, so Im not going to add on to that regard. But if your coworker chooses to come, here are some points to take into account when traveling

• Don't make it look like you going to be staying for a while.
• Be the gray man: don't take it literally, but don't dress fancy or to rugged. Blend in. If someone takes a photo of you walking by someone else, you don't want them to say "yeah he went over there".
• be situationally aware: don't be the bumbling idiot with a phone in there hand and earbuds in when walking in public. Keep your head up, wear sunglasses so people can't see where your looking. Stay alert.
• avoid the bad areas: do extensive research on the area your going.
• Cash is king: harder to track and create a profile about your purchases with cash. Don't carry to much otherwise that is a good questioning point
• shit hits the fan: if you noticed your being followed, stay calm and keep moving, make it look like your stoping in a store and go out the back door. Keep a change of clothes, hat and sunglasses. I'm not an expert on evasion but there are plenty of guides out there
• don't bring your personal electronics, use 2nd hand burners for your travels, just use them a bit before coming as to not raise suspicion.