Across a 12-hour shift, we follow the unsung heroes - the call takers, who are the first point of call in an emergency and can often make the difference between life and death.

Young call taker Antionette starts her shift at ESTA 000's ambulance call centre with a desperate call from a woman whose husband has just collapsed in the front yard and is now unconscious.

Call taker Luke starts his shift at ESTA 000's ambulance call centre with a call from a frantic mother, who has tripped and dropped her young baby.