One evening in July 2020, Seun [last name withheld], wearing his favourite vintage shirt, a baseball cap and sneakers, boarded a minibus from his home in Mushin to celebrate his 28th birthday with friends at Eleko beach in Lagos.

Midway between the drinks at the party, one friend brought out some balloons from a bag and a blue canister to inflate them. Soon, the entire group was sniffing the balloons.

It was Seun’s first time doing laughing gas, also known as nitrous oxide. He felt unbelievably good and started laughing uncontrollably until the night turned on its head for him at about 10pm.

“I always believed that I could handle any substance so I kept rushing it because it was just air,” Seun, now 31, told Al Jazeera. “It made me smile a lot, then something switched and my head went off. I started running into the water and my friends had to come and carry me. They kept telling me to calm down but I was unable to do that.”