Means you can't use it all the time. You do it for some time, then you have to stop and let your body rest before you can do it again. Read, and follow the instructions - if you insist on using it.
Usually 'a dry spell' if it occurs in an area where rain is common. If it is prolonged, meaning a long period of time, then it becomes 'a drought'.
When there's a long period of silence.
prolonged use of medicine is where you take one specific medication for a long period of time.
A person who is subjected to noise pollution over a prolonged period will likely suffer from hearing loss.
coma
drought drought
There was a rather prolonged period of silence when the professor finished speaking about the effects of nuclear war.
Bear Market
In poor light conditions and over a prolonged period, it can be.
Periodic is the adjective related to the noun period. Adjectives used to describe the word period include painful, prolonged, and heavy.
"A long discussion typically refers to a conversation that lasts for an extended period of time, whereas a prolonged discussion implies that the conversation is unnecessarily prolonged or extended longer than needed."
Failing to properly maintain the system and unprofessionalism are some of the factors that can cause the controls that have been established for a prolonged period of time to lose their effectiveness.