With pure nitrogen, you suffocate to death. I've heard it is actually painless, you just lose consciousness due to lack of oxygen.

A nearby school could never have felt the effects once it dispersed into the atmosphere.

I found the following at the link below:

Nitrogen gas can cause suffocation without warning. Store and use liquid nitrogen only in a well ventilated place.

As the liquid evaporates, the resulting gas tends to displace the normal air from the area. In closed areas, excessive amounts of nitrogen gas reduce the concentration of oxygen and can result in asphyxiation. Because nitrogen gas is colorless, odorless and tasteless, it cannot be detected by the human senses and will be breathed as if it were air. Breathing an atmosphere that contains less than 19 percent oxygen can cause dizziness and quickly result in unconsciousness and death.

https://www.tedpella.com/cryo-supplies_html/HandlingLiquidNitrogen.htm

Breathing pure nitrogen will kill you because there's no oxygen. 78 percent of the air is nitrogen gas, so people assume that nitrogen is not harmful. However, nitrogen is safe to breathe only when mixed with the appropriate amount of oxygen. A nitrogen-enriched environment depletes oxygen, and can be detected only with special instruments. If the concentration of nitrogen is too high (and oxygen too low), the body becomes oxygen deprived and asphyxiation occurs. Nitrous oxide ('laughing gas') is a compound of nitrogen and oxygen used as an anesthetic and it is administered in a mixture with oxygen, so for short periods of time it isn't dangerous like pure nitrogen.

its a gas, kept very cold...

So it freezes the lungs as well.

https://research.usu.edu/ehs/liquid-nitrogen/#:~:text=Liquid%20nitrogen%20is%20inert%2C%20colorless,(78%25%20by%20volume).&text=Cryogenic%20liquids%20are%20liquefied%20gases,C%20(%2D238o%20F).

It turns to a gas immediately once it is is released from inside a pressurized container and is no longer cold enough to harm you unless you re actually breathing it in directly from the nozzle. The injuries mentioned in that article I believe are due to breathing a high concentration of nitrogen, causing oxygen starvation.

Nitrogen is not toxic unless it is breathed in at great pressure (100 feet or more) below the ocean surface during a scuba dive. At 300 feet, nitrogen narcosis can cause symptoms that can lead to death. Spending too much time at depths of 30 feet or more can also result in crippling damage to muscles when a diver returns to the surface and bubbles of nitrogen escape the bloodstream and damage surrounding tissues.

But if you are close to the leak it would still be very cold.

the nozzle and took a deep breath. Le's stick to the facts.