Sam occasionally says "Great Fires of London!" in surprise.

Elvis occasionally says "Great Balls Of Fire!" in surprise.

The series of Fireman Sam does show people in peril and images of realistic fire which can be a little bit frightening but they end up getting rescued in the end and this show is completely immortal and has no emotional scenes

In fires, people are sometimes escorted from the fire wearing gas masks, and are put on stretchers. This is distressing.

The first five seasons has more intense scenes with people in trouble and fires, but it always turns out ok in the end. The later seasons has very mild scenes with people in trouble and fires.