While preparing for a trip to South America, I was warned, repeatedly, the altitude could be a real bitch. Depending on where you’re coming from (say, Long Island, which is sea level, or even Colorado, which ranges 6,000–7,000 feet) and how your body responds to steep elevations (some people are just naturally more susceptible), the side effects of altitude sickness can be rough: shortness of breath, headaches, nausea, vomiting. Generally the side effects sink in at about 8,000 feet, and can be a sucky reality for any traveling adventurer.

But after a few days in the Peruvian highlands, altitude sickness wasn’t the affliction that had me lurching to a toilet every 10 minutes. Nope—I fell victim to another common traveling sickness: salmonella.

In those dark, pukey hours, I learned a lot—about myself, about dehydration, and about the hellacious illness that was wracking my stomach muscles. May that fate never befall you—but if it does, here's what you need to know.