The Great Stink
"Exactly 150 years ago, an exceptionally hot spell of summer weather reduced the Thames flowing through London to a scandalous condition known as The Great Stink. Queen Victoria, travelling down the river to Millwall docks, had to contain her nause by clamping a bouquet to her nose. The fumes were not only foul but terrifying, since they were thought to be pestilential - the source of cholera [...]" (M. Black)
In the summer of 1858 London was beset by the "Great Stink".
On the one hand it was one of the hottest summers in London and on the other hand the Thames and many of its urban confluents were overflowing with sewage. The warm weather encouraged bacteria to thrive and the smell of untreated human waste was so overwhelming and almost unbearable that it even affected the work of the House of Commons and the law courts. But of course the parliament's members had an astonishing idea: they soaked the room's curtains in chloride of lime, the today's air freshener, and considered to relocate upstream to Hampton Court.
Heavy rain finally ended the heat and humidity of summer and the immediate crisis ended.
But every cloud has a silver living: the most evil- smelling summer gave the Londoners cause for thought, because they could not stand the smell any longer and had to start thinking about a solution, so a House of Commons select committee was appointed to report on the Stink and recommend how to end the problem.