This patch of tan-colored grass in our backyard had us stumped as to its origin. We had moved all the patio furniture to the grass, so perhaps a glass top on one of the tables magnified the sun rays? No, it wasn't quite the right shape. Did we spill something? The grass didn't smell and we couldn't remember dropping anything. Took us another couple of days to figure out that is where I parked the pressure washer to cool off after cleaning the patio so I could safely disconnect the water hose without burning myself.
Note to self. Leave the pressure washer on the patio.