Dangers of Time Traveling

Marty McFly: Wait a minute, Doc. Ah... Are you telling me that you built a time machine... out of a DeLorean?
Dr. Emmett Brown: The way I see it, if you're gonna build a time machine into a car, why not do it with some style?
- Back to the Future

Cracked.com offers 6 Time Travel Realities Doc Brown Didn't Warn Us About.

1. You'll age faster.
Say you travel in time for a year and then return home the exact moment you left. You're now a year older than friends and family who did not time travel.

2. Don't Drink the Water
Traveling in time is just like traveling to a foreign country. The local microbes will be different than your stomache is used to. And if you travel in the past, there won't be any health codes ensuring the safety of the food or drink you consume.

3. Say What?
How well to you read Shakespeare? (400 years old and considered "modern" English!) How about Middle English like Chaucer's Canterbury Tales? (700 years ago). Beowulf and Old English? (-1100 years, Hwæt! wē Gār-Dena in geār-dagum). Travel to Rome and hopefully you learned some Latin. Expect language to change in the future also, "Our brief govoreet through the letter-hole was not, shall we say, satisfactory, yes?" - from a Clockwork Orange.

4. May I see your license please?
You have no one and nothing to vouch for you when you time travel beyond your lifespan. No ID papers, no local references, no friends. You are alone and undocumented should you ever be detained by authority.

5. How will you be paying for that?
Modern coins and paper money will have you arrested for forgery if you try to spend them in the past. You'll need to buy some coins at an antique story or bring a commodity like gold. When traveling to the future, your money may be valid but after inflation it could have a higher antique value than face value. Recall that ten cents could buy a decent meal in the Great Depression. Try eating on 10 cents today!

6. Predicting the Future
A history book can give you a clue of what to expect in the past. But nothing can prepare you for what you might encounter in the future. A planet of apes? Conquest by terminator robots? Global plague? World war?

Bottom Line
Time travel at your own risk!