This has been a hot, wretched week in the Northeastern US. But as heat waves go, this one was pretty mild — especially compared to these seven examples.

It's easy to underestimate the danger of a severe heat wave, and more flamboyant weather events, like hurricanes, tend to draw more attention. But these slow-motion natural disasters can kill hundreds, or even thousands, of people at a time. And thanks to climate change, experts predict that they're only going to get worse. According to a recent Stanford study, prolonged heat waves could be common in the US by 2039.


So here are seven modern events that give us a hint of what to look forward to:

London, The Great Stink

Great Britain urbanized quickly in the 19th century, with half the population living in towns by 1851. Sadly, urban planning didn't keep up. Modern toilets appeared on the scene before modern infrastructure, turning the Thames into an open sewer. In June 1858, a heat wave hit London and baked the river into a fetid mess. "Gentility of speech is at an end - it stinks; and whoso once inhales the stink can never forget it and can count himself lucky if he lives to remember it," complained the City Press. Parliament moved upstream, and everyone who could afford it left town. Maybe this wasn't the hottest weather in English history, but it probably is the most spectacularly revolting weather event on record.


NYC & Philly, 1948

In August 1948, temps in New York, Philadelphia, and other cities flirted with the century mark for 5 full days. American's urban areas were big and bustling, with more people than ever were crammed together. To get out of the heat, they flocked to air-conditioned movie theaters and to airy beaches like Coney Island.

Time described the week:

In the big cities, as asphalt pavements softened to the consistency of taffy, hundreds of factories and offices began letting the help off early. When they didn't, the help just stayed away. There were 20,000 absentees in Detroit automobile plants on the day after the heat wave began. Attendance at big-league baseball games dwindled. Women went on sitting under beauty-parlor hair dryers (see cut) but only after stripping off half their clothes and donning toga-like sheets.


You can even see for yourself. Watch this clip from The Naked City, filmed on location in New York the same year (skip to the 4-minute mark):

Australia 2009

In January 2009, Melbourne saw three days straight of 109-degree weather. The resulting spike in AC usage blew out the city's electrical grid. Railroad tracks buckled in the heat, and brushfires burned in the east. 200 people showed up to a Friday night showing of Hancock, because the theater had stuck an inflatable screen in front of a swimming pool and sold tickets to get in the water.


New York City, 1977

The Son of Sam was on the loose, killing brunettes. The Yankees were fighting with each other instead of the Red Sox. A vicious heat wave gripped the city. People were primed for something crazy when the electricity started to go out. The brutal weather certainly didn't cause the looting and chaos that followed — but it wasn't exactly conducive to staying calm, either. And then even after the blackout, the heat still didn't abate.


One New York Times reader reminisces:

What with the heat, the fire hydrants fanning out big sprays across the streets full of sweaty people, the looting, no subways, little work, no elevators, no refrigerators, Son of Sam roaming around, boyfriend sick, and punk rock as the sound track in my young head, Blackout '77 was a surreal, fun, scary holiday in New York City near its glorious nadir.


North America, 1936

Heat waves are often an urban problem, but high temperatures can create big problems in rural areas, too. A hot, dry summer is bad enough, but this one followed one of the coldest winters on record. The impact on the nation's food supply was dramatic: The Dust Bowl had already turned the Great Plains into a vast wasteland, and farmers across the continent lost their summer crops. And the cities baked. Even if widespread air conditioning had existed, most people would have been too poor to afford it, as it was the depths of the Great Depression. At least 5,000 people were killed, many in urban areas like Chicago and even as far north as Toronto.


Chicago, 1995

The CDC had warned American cities for years they needed emergency plans for extreme heat, but few listened. In July 1995, Chicago got walloped with triple-digit temperatures, exacerbated by high humidity. Desperate for a way to cool off, people opened so many fire hydrants that many buildings lost water pressure entirely. Social forces combined with an ineffective response to make this an unusually deadly heat wave. Many victims were elderly and lived alone, often in neglected neighborhoods with high crime. That left them afraid to leave their homes, but with no one to check on them. Then the city government didn't respond fast enough, refusing to call in extra staff or ambulances and waiting until bodies piled up to declare an emergency. Because no one could agree on what "heat-related deaths" mean, estimated casualties range from 400-700 people.


Europe, 2003

In 2003, a record-breaking heat wave swept across Europe. In many places, temperatures climbed north of 100 degrees and stayed there for two weeks. Most people on the continent don't even have air conditioners. France fared the worst with an estimated death toll of 14,000 people, mostly elderly. Forest fires plagued Portugal. Melting glaciers caused flash floods in Switzerland. Crops failed in Southern Europe. All told, between 20,000 and 35,000 people died. That's why Dr. David King, a scientific advisor to the UK government, called it the biggest "the biggest natural disaster in Europe on record."


Top image, and smokestack and bear images, by AP Photos.