Petty theft is common in Arequipa, so leave anything of value back in your hotel. Theft can also be a problem in the market areas, especially after dark. Be careful about taking a taxi at any time of day (but particularly after dark), especially at the bus terminals, as car-jackings and robberies have been reported. It is best to pay the few soles more for a radio taxi that your hotel or restaurant can call. The tourism office warns not to contract tourism services on the street or at the airport or bus terminals, as you run the risk of being scammed or worse.
The sun is strong in Arequipa; use a hat, sun block and other protection. Tap water in Arequipa is not potable; treat or boil before drinking, or use bottled water.