Final answer:
The first action a nurse should take when someone has a minor thermal injury is to flush the affected area with copious amounts of cool water to cool the tissue and reduce pain.
Step-by-step explanation:
When a nurse encounters a situation where someone sustains a minor thermal injury, the first intervention should be to flush the area with copious amounts of cool water. This initial step helps to cool the area, reduce pain, and prevent further damage to the tissue. It is important to avoid applying antimicrobial ointment, removing jewelry, or pulling off clothing that may be sticking to the burn before flushing the area with water, as these actions can cause more harm or complicate the injury.