TORONTO - Dr. Jay Keystone is a close friend and my most valued mentor in the field of tropical medicine. When he speaks, I listen — and so should you — especially when it comes to his 10 Commandments for international travel. Dr. Keystone’s 10 travel commandments rival Fulghum’s All that I needed to know I learned in Kindergarten — simple in text; profound in application. Prepare ahead, post these reminders on your fridge, and practice the principles as you travel. By following these healt...