When a doctor or nurse sticks a needle into someone's arm, that hurts.
Lots of kids - and even quite a few grown-ups - are afraid of getting shots. But the injections often necessary for things like immunizations, medication, and conditions like allergies and diabetes.
When I was a kid I had to get allergy shots for about two years and I learned a secret to keep them from hurting. At least to keep them from hurting much.
It all depends on what you're thinking.
If I was worried that the shot would hurt when the needle went into my arm it would hurt a lot more than if I was thinking about other things. That was probably because being nervous makes muscles tense up, and an injection into tense muscles hurts more than one into relaxed muscles.
Just as actors try to think what the character they're portraying would be thinking and that shows in their facial expressions and body language, if someone thinks about something happy or peaceful their whole body becomes calm and relaxed.
It's a good idea to encourage kids waiting to get shots to think about the most wonderful thing that could happen to them, or to imagine a magical world where everything is perfect and to tell you about those ideas while the shot happens.
There's no guarantee the shots won't hurt, but the pain will be much less if they think about things like that. It works for grown-ups, too.