What should be done first when treating a casualty with a thermal burn?

The primary step in managing a casualty with a thermal burn is to stop the source of the burn. This is crucial because continuing exposure can exacerbate the injury, leading to deeper tissue damage, more severe burns, and a higher risk of complications. By eliminating the source, such as removing the casualty from the heat or extinguishing flames, further injury is prevented, allowing for more effective treatment of the burn itself.

While assessing for additional injuries, applying a cool compress, and administering pain relief are all important aspects of burn care, they should follow the immediate action of stopping the burn source. This prioritization is essential in ensuring the safety and health of the casualty.