Authorities in California have stepped up heat warnings after a couple died of exposure in Joshua Tree National Park. The bodies of Dutch music promoter Augustinus Van Hove, 44, and his German girlfriend, Helena Nuellett, 38, were found along a park road after a day in which temperatures soared as high as 105, reports the Los Angeles Times. Their rental car had become stuck on a dirt road in the park, which is bigger than Rhode Island and covers parts of the Mojave and Colorado deserts.
Park rangers, who warn that cell phone coverage in the park is very limited, believe the couple died while trying to trek to a main thoroughfare. Visitors should carry plenty of water, ensure their vehicle is in good working order, and "have a plan," warns a public information officer at the park. "When you're traveling out there in your car, you've got the AC going, you feel pretty protected and secure. You never really feel like you're 10 minutes away from a dangerous situation—but that can all change at a moment's notice." (More California stories.)