The holiday season came to subequatorial South America on the crest of a blistering heat wave. In Santiago, Chileans sipping their traditional cola de mono (monkey's tailmilk, cinnamon, and coffee laced with aguardiente), fanned themselves as the thermometer climbed to 93°. At Viña del Mar and Uruguay's Punta del Este, beaches were jammed. So was the graceful white curve of Rio's Copacabana, where young cariocas, lampooning a recently revived city ordinance against walking to the beach in bathing suits, donned dinner coats or silver-fox jackets over their beachwear.
Christmas shoppers along Buenos...