He fainted on the train in China.
But, instead of helping the man, the other passengers fled the carriage.
When the Shanghai train reached the next station, there was a massive stampede for the exits, the South China Morning Post reported.
The incident was captured by onboard cameras on Aug 9 and was released yesterday by broadcaster CCTV.
The video shows the foreigner blacking out and then slumping sideways in his seat.
He then rolls onto the floor as passengers run away from the carriage.
The footage also shows them scrambling out of the train at the next stop. One man was almost trampled in the resulting stampede. The foreigner is later seen getting to his feet. He looks dazed as two people, most likely train station staff, enter the train. He takes a seat as they leave after inspecting the carriage.
The commotion may have been partly caused by a passenger shouting, "Accident!" after the Caucasian collapsed, according to CCTV's description of the video.
Seen 13,000 times
The video has been viewed more than 13,000 times since it was posted yesterday. It received more than 4,300 comments and nearly 2,000 shares on micro-blogging site Weibo in just an hour.
Netizens criticised the passengers for their behaviour, but some said recent terrorist incidents may have led to the extreme reaction.
Blogger Li Zhe Ren said it was not surprising due to alleged extremist incidents in Yunnan and Xinjiang provinces in recent months.
One of these occurred at the Kunming train station in Yunnan province in March, when men armed with knives went on a slashing rampage. The Chinese authorities blamed Xinjiang militants for the brutal act, which left 29 civilians dead and 143 wounded.
Mr Li said: "People have been strained and are a bundle of nerves nowadays as terrorist attacks have been widespread all over the world.
"In the closed space of a subway train, a stranger's abrupt collapse… can trigger every frightened person to flee from the scene."
This article was published on Aug 21 in The New Paper.
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