A pregnant woman has issued a warning after her iPhone 7 'left her with a massive burn'.

A pregnant Sydney woman has claimed she suffered second-degree burns to her arm after leaning on her new iPhone 7.

Sharing her story on Facebook, Melanie Tan Pelaez said she accidentally fell asleep on top of her charging mobile phone when she was woken by a “sudden pain, pins and needles, numbness and shortness of breath”.

“I went to get dressed and realised my arm was very red, so I then went to the GP and they advised me I needed to go straight to the hospital,” she told news.com.au.

The thermal burn she sustained spans from the middle of her forearm to the middle of her bicep. Ms Pelaez said she has been in consultation with a plastic surgeon about treatment for the resulting scar.

“Apple took my phone and details, but said it couldn’t have been the phone because it didn’t have a distinct smell,” she told news.com.au.

“I then got a call from a member of the executive team who told me they were now handing the matter and had sent the phone to a senior technician in California for testing.”

Mamamia understands that Apple is currently investigating the incident.

Melanie Tan Pelaez wants to warn other iPhone 7 users. Image: Facebook.

On Friday, Ms Pelaez shared her story on social media as a cautionary tale to other iPhone 7 users:

"PLEASE be careful," she wrote.

"I have been an iPhone user since the beginning and have never had an issue or concern, so it's really scary and disappointing that something like this happened and can happen to someone else."

According to news.com.au, Pelaez has been offered a replacement phone by Apple, but has declined because she no longer has trust in the device.

Apple is yet to issue a comment.