I travel quite a bit, with a few trips internationally every year. One item that you should always carry: IMMODIUM.. Been there done that..

It is critical that the person understand the customs and law. Find out as much about the places you are going to. For example, in Mexico City or Bogota, for the most part, you cannot trust the police... They have commited murders, rapes etc. Mexico City is the crime capital of North America, and Bogota is the crime capital of South America. Try to avoid the police as much as possible, but sometimes it's unavoidable - random road stops.. Know the proper ways to bribe them as well as keeping money in several separate places..

In regards to the pepper spray, I would double, triple, quadruple check the local laws. Depending on the different penal systems, it might be a fine to many many years in jail, and please note, they are not American jails where you can reasonable expect clean food and cells.

For the most part, you should book your hotel prior to arrival. I tend to lean more towards US or European chain hotels (more on the higher scale). They can provide safety information. For instance, when travelling alone and obviously a visitor, you should never ever take a public taxi in Mexico City (the little old vw beetles). Thats a sure fire way of getting kidnapped. Oh, and kidnapping is a booming market in developing countries.

Pain killers and other drugs should be left at home, and purchased there. Bringing narcotics into most countries will result in the death penalty. Some places, it's practically immediate - No such thing as an appeals process.

Be smart, be aware, and understand the customs, cultures and laws. All the locals will know you're a vistior even before you talk. It can be as simple as the shoes you're wearing, or the plain fact that you are wearing glasses (sun or prescription).