In an ideal world yes they should be warned as early as possible, so they can be prepared," he said.
"If this happens out of the blue and they're not prepared then it could have really nasty effects for a lot of people when they're not expecting it."
He said asthmatics could certainly be affected by this level of smoke.
"On these kinds of days they need to stay in doors, they need to make sure they've used their preventer medication and use their reliever medication."