In the U.S., we've grown accustomed to greetings of chilled air when we enter nearly any building on any day over 75 degrees. Air conditioning isn't common in Europe, but with deadly heat waves hitting the continent regularly and only projected to worsen over the rest of the century, cooling off is becoming, literally, a life-and-death issue. Instead of settling for conventional air conditioning technology, European researchers are experimenting with cooling methods that don't rely on environmentally damaging refrigerants. As they stand, even the most cost-effective ways to run air conditioners aren't tempting enough to drive widespread adoption. Still, with such increases in heat-related deaths, the onus is on Europe to find a way to save lives and the planet at the same time.