Vomiting man attacks woman trying to help him

A Chicago man is being hunted by police after hitting a security guard so powerfully she required hospital treatment - all after she tried to help him while he vomited in the street.

CCTV footage captured the incident, which took place outside a nightclub at about 2am on Sunday morning (local time) and shows part-time security guard Zoa Stigler approaching the man.

As he was spewing on the footpath, she went inside the club to get a bucket to his vomit off the ground - but when she emerged back onto the street, it all started to go terribly.

The man doesn't take kindly to her trying to help him, and immediately throws a bottle of water at her before punching her squarely in the face and walking off.

The blow broke Ms Stigler's nose and also left her with a fractured eye socket, blurred vision, numbness and headaches. She was immediately taken to hospital and now requires surgery.

A fundraising page was set up on crowdfunding site GoFundMe to help Ms Stigler pay for the surgery, and it has since raised US$13,230 ($19,220) in pursuit of her US$20,000 ($29,060) target.

Police are still investigating the incident and trying to track down the man - and they've warned that the offender will face a misdemeanour charge if found.