A heat wave is reached when there are three or more consecutive days in which the mercury reaches 90.Extreme heat stands as the No. 1 weather-related cause of death in the United States, claiming more ...

Summer will make a dramatic entrance in the U.S. this week with a heat dome that will bring stifling temperatures and uncomfortable humidity to millions.

Here are some of the key warning signs to watch for when temperatures rise – and ways to keep cool when the heat and humidity get too high.

Summer will make a dramatic entrance in the U.S. this week with a heat dome that will bring stifling heat and uncomfortable humidity to millions.

Summer will make a dramatic entrance in the U.S. this week with a heat dome that will bring stifling temperatures and uncomfortable humidity to millions.

Summer will make a dramatic entrance in the U.S. this week with a heat dome that will bring stifling heat and uncomfortable humidity to millions. The heat will be particularly worrisome this ...

Heat dome will blanket much of the US, with worrisome temperatures in Midwest Summer will make a dramatic entrance in the U.S. this week with a heat dome that will bring stifling heat and ...

Summer will make a dramatic entrance in the U.S. this week with a heat dome that will bring stifling heat and uncomfortable humidity to millions. The heat will be particularly worrisome this ...