"The princes are in a sterile field, it's best not to chance compromising that."

He forced himself to gaze past the blue light of the sterile field.

"I was really moving down the hill," he told her, looking anywhere but at the sterile field and the needle.

At the center of it all, though, was that cautionary requirement of a sterile field.

I was finally able to understand what the wizards who created Orden meant about the sterile field.

"I think you can see why the wizards who created Orden were so concerned about preserving the sterile field."

Or of her lashing out with unbound hands into the sterile field in which the baby was to arrive?

He knelt by the table a safe distance from the sterile field.

Glancing around, he quickly retrieved them and brought them back into his sterile field.

When done at bedside (that is, in the patient's room), a suitable sterile field must be established and maintained throughout the procedure.