The iPhone 4s often freezes around half a minute into a phone call to emergency number 112 and has failed in a few serious cases.
Neyðarlínan, the Icelandic Emergency Services, has contacted the Apple company in USA because of the problem, RÚV reports.
It seems that if the iPhone 4s is set to 3G when a call to 112 is made, it disrupts the phone call after 20-40 seconds and the phone freezes, causing the caller to have to turn it off and on again, a process that can take 1-2 minutes.
The delay can be a critical factor in whether paramedics reach the emergency soon enough.
iPhones have frozen in a few cases where the emergency was quite serious and staff at Neyðarlínan has taken up advising callers to call again from another type of cell phone or use a landline phone.
The reason why this only happens when the emergency services are called is because the number 112 is programmed in the iPhone 4s.
Jónas Guðmundsson, spokesman for Iceland Search and Rescue told RÚV that to be on the safe side, iPhone 4s users should use the 112 app, which enables staff at Neyðarlínan to see where the phone is located as soon as a call is answered.
He added that the problem does not arise every time an iPone 4s is used to call 112 and to go around the problem, it’s best to turn off the 3G when the phone call is made.