Some of the temperatures were so high as to be downright eccentric. Everyone expects Phoenix or Las Vegas to be toasty in July, but 105F (41C) was little short of stunning in Denver, the usually temperate Colorado capital on the very edge of the Rockies. Grand Junction, on the western slope of the Colorado mountains, hit 106F, as did Pueblo, in the southern part of the state.
Meteorologists said they had counted more than 200 new temperature records in the latter stages of the week - including readings well over the 100F mark in suburban Los Angeles, Utah, New Mexico and elsewhere. Las Vegas, which has registered six deaths, spent much of the week hovering around 115F (46C).
In California's Death Valley, usually the hottest place in the western hemisphere, where winter rains had led to a riotous outburst of spring flowers earlier in the year, the mercury rose to 129F (54C). That, interestingly, was not a record - Death Valley's top temperature, recorded in 1913, was 134F.
In Phoenix, Arizona, homeless people made up 14 of the registered deaths from the heatwave. The others were mostly elderly, including 97-year-old Albert Pinkerton, whose home temperature was measured at 110F when police found his body early in the week. His 88-year-old wife Louise was severely dehydrated but survived.
In California, electrical grid operators called a Stage 2 emergency, meaning the power supply was down to its last 5 per cent, triggering several automatic saving mechanisms.
As lawn sprinklers and air conditioning systems went at full tilt, memories were revived of the "rolling brownouts" that afflicted the state four years ago. State officials said, however, they saw no immediate signs of a similar crisis now.
Weather forecasters offered the chance of a temporary respite, as cooler, wetter air moves in across the country from Hurricane Emily, which made landfall on the Gulf coast of Mexico and southern Texas last week and has headed slowly west as its intensity has gradually dropped off.
The so-called monsoon season in the American West - marked by cloudy afternoon skies and rain showers - is at least two weeks late this year, but may now start with Emily's encouragement.
Forecasters also said, however, that the soaring temperatures showed every sign of lasting, on and off, until the end of the summer. The West is already suffering a protracted drought which has caused reservoir levels to drop and led to considerable pain for the region's farmers.