Breaking down heat-related alerts & what they mean

NORTH TEXAS (CBSNewsTexas.com) — Triple-digit temperatures are making their unwelcomed return to North Texas, with the National Weather Service (NWS) issuing an Excessive Heat Warning for Monday and Tuesday. An Excessive Heat Warning is the highest heat-related alert and means those in the issued area need to take action. But what do the other alerts mean? According to the NWS, an Excessive Heat Warning is issued within 12 hours of "extremely dangerous heat conditions." But what is considered dangerous heat? Well, they say it's when the maximum heat index temperature...