Despite what you've seen in the movies, tarantulas are not inherently aggressive and are more likely to skitter away rather than bite you. Of course, if you pick one up you're asking for trouble. Even better news is that most tarantulas do not deliver fatal bites although some people experience serious allergic reactions.
If a tarantula does happen to crawl on to you, attempt to brush it off with a stick or some newspaper. If that doesn't work, you can also try standing up slowly and then bouncing up and down gently.
If you happen to be bitten by a tarantula, don't panic. Most first bites are dry, that is they are free of venom. It's the second bite that usually contains the venom. If the bite, in your case, is dry, treat it like any other small wound. Once bitten, check the area regularly to see if there is redness and / or swelling. Should pain and tenderness persist for greater than 12 hours or if other serious symptoms appear, seek medical attention as quickly as possible.
Antihistamines can be used to deal with allergic reactions, although they work slowly. If the reaction is particularly strong, epinephrine might be called for. Something you're probably not going to have handy so again seek medical attention.
Finally, even with a dry bite, watch out for signs of infection. Infection could actually kill you so you want to address it if you notice muscle stiffness, spasm, fever, convulsions, difficulty swallowing, vomiting, swollen nymph nodes, chills, shock, rapid breathing, or an irregular heart beat.
Some important points to remember to help you avoid tarantulas:
- Tarantulas are not carriers of any known disease that affects humans.
- They are found in North America west of the Mississippi River; in South America; and in warm climates throughout the world.
- Their habitats include deep deserts, grassy plains, scrub forests, and rainforests.
- Most live in burrows, but a few species prefer trees.
- Tarantulas are mostly nocturnal and are difficult to notice.
- Most encounters are with adult males which wander around during daylight hours looking for female mates.
The Worst Case Scenario Survival Handbook – Travel by Joshua Piven and David Borgenicht