This is the 18390th most frequent Russian word.
экстренные
"Urgent" or "emergency."
In this sentence, 'экстренные' describes 'службы' (services) as emergency-related, indicating their role in urgent and critical situations.
Экстренные службы прибыли на место происшествия.
Emergency services arrived at the scene.
Here, 'экстренные' qualifies 'меры' (measures), emphasizing that these actions were taken in response to an urgent situation.
Во время шторма были приняты экстренные меры.
During the storm, emergency measures were taken.
In this example, 'экстренным' is used as an adjective modifying 'ситуациям' (situations), denoting situations that require immediate attention or action due to their urgency.