This is the 2666th most frequent Russian word.
экстренных
"Экстренных" means "emergency" or "urgent."
The word 'экстренных' here is used to describe 'случаях' (situations), indicating that the situations are urgent or emergency-related.
При оказании помощи в экстренных случаях важно сохранять спокойствие.
When providing help in emergency situations, it is important to stay calm.
In this sentence, 'экстренных' modifies 'служб' (services), specifying that these are emergency or urgent services, such as police, ambulance, or fire department.
Экстренных служб вызвали на место происшествия.
Emergency services were called to the scene.
Here, the word 'экстренных' modifies 'условиях' (conditions), highlighting the nature of the conditions as emergent or requiring immediate attention.