It's 4 p.m. in Joshua Tree National Park and the air temperature is hovering around 99 degrees -- relatively mild for an August afternoon. But at ground level, the sand along the popular Hidden Valley Nature Trail has reached a scorching 136. "I don't want my bare feet on that," says ranger Anna Marini as she shows her thermometer gun reading to a couple visiting from Switzerland, who are appropriately awed. Marini uses the tool as a prop to engage hikers traversing this surreal desert wilderness that's roughly the size of Rhode Island. As the coordinator of the park's Preventative Search and Rescue Program, her mission is to protect visitors from hazards that include extreme heat, razor-sharp cacti and thirsty bees.

Vacuums are the most successful consumer home robots ever, and they're likely to remain so for quite a while, simply because they do quite a good job at keeping your floors clean in a reliable and affordable way. For robot vacuum manufacturers, this is a bit of a problem: As we very often point out in our reviews, lower-end models clean just about as effectively as more expensive ones, often making it difficult to justify an upgrade. Today, Neato Robotics is introducing a new flagship robot vacuum that we think offers one of the most significant advances we've seen in years: persistent, actionable maps. Like its predecessors, the D7 uses a lidar sensor to create a map of your house as it goes, but now, the robot will remember that map and allow you to interact with it. Neato is starting off simple with what you'll be able to do (like defining no-go zones), but it's an incredibly powerful feature that's necessary for the future of all home robots.