why phone is getting frozen?
@Wat Conditions does the iPhone SE screen gets blank or frozen?
What needs to be done to avoid this?
Question marked as
There may be a number of reasons that an iPhone's display will "get blank or frozen." However, without more information from you, it would be difficult to tell you what they are.
Regardless, what have you tried, so far yourself to resolve this so that we don't try offering potential solutions that may not have already worked for you?
Ref: If your iPhone won't turn on or is frozen - Apple Support