Heat warnings and heat advisories are a lot different from other severe weather warnings. Each forecast office gets to choose the parameters with which to issue a warning. In southeast Texas, the Houston/Galveston National Weather Service will issue a heat advisory when the heat index, or feels-like temperature, goes above 108 two days in a row. The NWS in SE Texas also does NOT issue heat warnings. The advisory is as high as it will go. It seems strange when Dallas is under a heat warning and we have an advisory with both of us suffering the same effects from the heat. The reason each office gets to choose the parameters regionally is heat affects each part of the country differently. Minneapolis may issue a warning if the temperature is 90 degrees and it feels like 100. They simply aren't used to the heat. The desert southwest may not issue a warning until the actual temperature rises above 110.