In September, Chicago-based lawyer William Pintas was relaxing by the pool at the front of the Vdara Hotel in Las Vegas, where he co-owns a condominium. The sunny day proved problematic, however, when his head became so warm it felt as if it might catch fire. In fact, Pintas later said that he could smell his hair beginning to burn. Turns out, the hotel itself had targeted Pintas with a particularly vicious solar beam. The Vdara, which opened in December 2009 as part of Vegas’ new City Center complex, has a concave front filled with highly reflective windows. From a bit before noon to about 1:30 pm every day, the sun reflects off the windows, sending a focused spot approximately 10 × 15 ft across the ground in front of the building, including the patio area around the hotel’s pool. Not long after the building opened, employees and regulars took notice of the “Vdara death ray.” Noting that the beam disintegrated the heat-absorbing black lettering on a plastic shopping bag that he’d had with him, Pintas estimated that the beam spiked the temperature at poolside to 120 to 130 °F. During the design phase, the potential for problems with a so-called “solar convergence” was anticipated, and the south-facing windows were covered with a high-tech film designed to scatter most of the reflected rays. Although the “death ray” remains, no one has been seriously injured thus far, and the hotel is working on measures to mitigate the sun’s effect on its patrons. The Vdara is not the only building that exhibits solar convergence issues. For example, the steel walls of the Disney Concert Hall in Los Angeles had to be sanded to reduce its own heat beam effects. Still, architects should consider passing their bold design ideas through capable ray-tracing optical software, to be on the safe side.