An ISO 7010 style 'emergency telephone' sign, without the 'cross' symbol in the top right and with the telephone centered on the green field. This is used in situations where a telephone for requesting emergency assistance is provided, but it's not specifically for medical care, and instead contacts: general emergency services, an equipment control room, security office, etc.
This vector image includes elements that have been taken or adapted from this file:
ISO
Base file: MaxxL
This file: The Navigators