Physical Danger
Depends a lot on how ambitious you are with your missionary work. On a day-to-day basis, barring super extreme circumstances, the biggest danger you'll encounter will be a possibly venomous snake. Some countries (think formally occupied, politically unstable ones with state religions at odds with yours) can be particularly dangerous to work in. If a "situation" crops up, pay close attention to what your embassy says and actually do what they say. Leave, if they say leave. You can come back and convert souls later. Remember, missionaries are often targets of harassment, raids, kidnappings, and a whole host of not such fun things. The occasional missionary ends up killed. Talk about sacrifice.