 From Little Rock Public Radio, I'm Nathan Treese. As extreme heat grips the nation, those hoping to understand heat's real-time risks are turning into a relatively new CDC tool, the Heat and Health Tracker. It can help individuals understand risk, too. Plus, Jeff London, who covers Broadway for NPR, is an avid cyclist. When he heard about a nonprofit that pairs sighted riders with blind and low-vision riders, he checked it out.