From the Addison Fire District:

Protective equipment such as bullet-proof vests and ballistic helmets are becoming more of a common place among paramedic / firefighters today. There is a growing concern that shooting victims need to be treated quickly. In the past the police would secure the scene then the paramedic / firefighters would go inside to treat them. In a task force response a team of police and paramedic / firefighters now enter an active scene to treat and remove victims.
The Addison Fire Protection District will soon outfit on-duty paramedic / firefighters with protective equipment that will allow them to become part of a response task force during an active shooter incident and help protect them during questionable situations. 

The District has approved an expenditure of $16,283 dollars for protective vest and ballistic helmets. The gear will be kept on the vehicles and be ready for use when needed. “We can no longer be passive; we must respond with the police and render emergency medical care in a timely manner,” said Fire Chief Joe Leone. “We have instituted training, purchased the protective equipment and are now ready to enter into this unfortunate realism.”
Addison Fire District issues tactical vests

Addison Fire District photo