Phoenix — The first heat wave of the season is bringing triple-digit temperatures earlier than usual to much of the Southwest U.S., where forecasters warned residents Tuesday to brace for “dangerously hot conditions” with highs expected to top 110 degrees Fahrenheit (43.3 Celsius) in the days ahead in Las Vegas and Phoenix. By Wednesday, most of an area stretching from southeast California to central Arizona will see “easily their hottest” weather since last September, and record daily highs will be in jeopardy throughout the region, the National Weather Service said. [time-brightcove not-tgx=”true”] Excessive heat warnings have been issued from 10 a.m.