When the mercury climbs and summer's heat calls for a remedy, the practical solution is an ice-cold drink. In Texas, and around the country, that often means Margaritas, the beloved cocktail combining tequila, orange liqueur and lime juice. But for an extra cooling option, make it a Frozen Margarita, a Dallas invention dating back to 1971. Mariano Martinez opened Mariano's restaurant that same year and quickly established it as one of the best places in town to get sizzling fajitas and blended Margaritas. But he had a consistency problem. Serving so many guests each night, some drinks were rushed and unmeasured, while others sat too long at the bar and began to melt. He wanted a way to streamline the process so that each guest received a perfect cocktail. The answer came from an unexpected source: the Slurpee machines at 7-Eleven. After witnessing the machines in action, Martinez realized that he could apply the same principle to his Margaritas and outfitted an old soft-serve ice cream machine to pour the tequila-based drink. His problem was solved, and the slushy, uniform cocktails were a hit. Maybe you have a Margarita machine at your home, in which case, you probably throw a great party. If not, you likely have a blender. And sure, a Margarita tastes great whether you're drinking solo or serving a group, but the blender really shows its value when you're making multiple drinks at once. In that case, you can scale up the recipe to account for the number of servings you require. Blend a big batch, and you can provide glasses to all your friends, which keeps everyone happy and keeps you from having to play bartender all night. Martinez wasn't the first person to blend a Margarita with ice, but he did invent the machine-made version that helped to popularize tequila, Tex-Mex joints and Mexican restaurants in America. As for that original machine: It can be found at the Smithsonian National Museum of American History in Washington, D.C. The History and Secrets of the Margarita