Final answer:
The first intervention for a minor thermal injury is to flush the area with cool water.
Step-by-step explanation:
When treating a minor thermal injury, the home care nurse would first intervene by flushing the area with copious amounts of cool water to help cool the burn and remove any heat source. This step is important to prevent further damage to the skin and tissues and can help alleviate pain and reduce swelling. It is essential to apply cooling water to the burn as soon as possible to provide immediate relief and minimize potential complications.