The most common and most likely answer to this crossword clue is the 7 letter word HOTLINE
I've seen this crossword clue in The Times
H
O
T
L
I
N
E
More clues leading to the result HOTLINE
- Emergency provision in hotel out of order
- Special phone service arranged in hotel
- Fashionable to take a bit of coke? It helps in an emergency
- In crisis, leaders use this hotel in Barking
- Special link for mobile in hotel
- Means to communicate urgently what’s selling out
- Emergency set-up, product that sells quickly
- Does this crisis phone service remain unused during a cold war?
- Then oil spoilt emergency contact
- Special phone link may cause heated row
Buddy explains!

The straight part
We know that "It helps in an emergency" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case it helps in an emergency = hotline.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does HOTLINE mean?
HOTLINE noun- A telephone line that is always staffed and able to give immediate assistance.
- A direct line between two people, especially one between heads of state to be used in an emergency.
- To communicate over a telephone hotline.