Wynn Resorts, Las Vegas Sands, Boyd Gaming and Station Casinos have installed screening mechanisms at every accessible entrance of their properties. At Wynn Las Vegas and Encore, as well as The Venetian and Palazzo, thermal imaging cameras give the operators a “Predator”-style look at everyone who enters. Downtown casinos, including The D and the Plaza, rely on a mix of wrist and forehead scans. The longer you’re out in the Las Vegas heat, the warmer your exposed skin will register, experts say. As a result, you may be asked to wait and cool off before entering, even if you aren’t feverish.