The clip has so far been viewed more than one million times and clocked up 24,000 retweets and 26,000 likes.
Photos taken after the incident by Ms Olivas reveal the phone's screen detached from the battery with a completely melted side bezel.
Screengrab of tweet by Brianna Olivas
She explained later on Twitter that she was asleep while her device caught fire and her boyfriend moved it away from her.
Ms Olivas told the BBC: "I realized there was a problem a day before it blew up. It would not turn [on] so I took it into a store and they were able to get the phone on and they ran diagnostics and said nothing was wrong with the phone."
She said the phone, which she had bought in early January, was on the bed next to her head. Her boyfriend moved the phone to the dresser, before noticing something was wrong.
"From the corner of his eye he saw the phone smoking and heard a squealing noise coming from it. He quickly ran over to the phone but by the time he got there it had already caught fire, he didn't have enough time to throw it out the front door so he quickly threw it in the restroom."
Ms Olivas added that Apple has replaced her phone and the case. "They said they had never seen anything like this before."
Watch the video below:
She said the phone, which she had bought in early January, was on the bed next to her head. Her boyfriend moved the phone to the dresser, before noticing something was wrong.
"From the corner of his eye he saw the phone smoking and heard a squealing noise coming from it. He quickly ran over to the phone but by the time he got there it had already caught fire, he didn't have enough time to throw it out the front door so he quickly threw it in the restroom."
Ms Olivas added that Apple has replaced her phone and the case. "They said they had never seen anything like this before."
Watch the video below: