The quality of health care in Puerto Rico  is comparable to that in the United States, and all major towns have one or more hospital and pharmacy, including Walgreens. Unlike in Mexico, the water is as safe to drink as it is in the United States, and fruits and vegetables are fine to eat.
There are no major health issues facing the island, save the occasional outbreak of dengue fever, a viral infection spread by mosquitoes. Symptoms include fever, headache, body aches, and a rash, and it lasts about seven days. In rare cases it can be fatal—usually when the victim has been previously infected with the disease. Visitors are at low risk for contracting dengue fever unless there’s an active outbreak, but using mosquito repellent is a good preventative measure.
A visitor’s biggest physical threat is most likely sunstroke. Summer can be brutally hot, especially in urban areas. It’s important to drink lots of water, especially if you’re doing a lot of walking or other physical activity. A hat and sunscreen are recommended. Or you could do as some of the local women do and use umbrellas to keep the beating rays at bay.
Most of the crime in Puerto Rico  revolves around the drug trade. The island is on a drug-transportation route that begins in Venezuela and passes through the Dominican Republic and into Puerto Rico on the way to the U.S. mainland. Add to that a poverty level of 44 percent, and you have a certain level of desperation. Ponce  and Loíza  have experienced high rates of murder, but most crimes are of the petty street variety—especially theft from automobiles or snatched purses. The street drug trade in San Juan  operates out of La Perla, a former squatter’s village outside the city wall beside Old San Juan .
Prostitution is illegal in Puerto Rico, although there’s at least one strip club in San Juan that’s reputed to be a bordello. Prostitutes do sometimes work the streets—even in quiet towns such as Mayagüez—and they’re often more likely to be transgendered men than women.
The most common threat to visitors is having their possessions stolen from a rental car. Never leave anything of value visible in your car and always keep it locked. There are also occasional reports of carjackings and stolen vehicles. The police patrol San Juan regularly, and they keep their blue lights flashing all night long to announce their presence. For any emergency—crime, fire, wreck, injury—dial 911 for help.