If someone shows signs of heat stroke, such as a high body temperature, confusion, and hot, red, or dry skin, what is the most critical immediate action to take after calling for emergency help?

✓ Correct Answer: Option B

Heat stroke is a medical emergency. After calling for emergency services, the priority is to rapidly cool the person's body (e.g., with cool, wet cloths, a cool bath/shower if conscious) while waiting for help. Giving fluids might be done if they are conscious and able to swallow, but cooling is paramount.