Kai Cenat is facing some legal heat ... because his company is getting sued by a man who claims he nearly suffered a heatstroke not once but twice at one of Kai's Streamer University events.

In the lawsuit, obtained by TMZ, a guy named Caleb Gottfried aka SNRVK claims he attended Kai's Streamer University event at a college in Manhattan last month ... and conditions at the event were so severe he had two separate near misses with heatstroke ... and NYPD officers were there to witness it!

Adding insult to near injury ... Gottfried says his image was used in a commercial for it without his consent. 

In the docs, Gottfried says Kai used him as "background talent" for the commercial, but says he never received any sort of release or waiver paperwork to give his consent to the usage. 

He blamed the alleged near heatstroke on "negligent crowd control and total failure to provide standard safety and ventilation measures" at the event. He's suing for more than $330,000 in damages.

The hits keep coming for Kai ... he's also being by a different man claiming he got beaten up by a member of Kai's security team.

We reached out to Kai's camp ... so far, no word back.