What is the first step to care for an elderly person who is suffering from a high body temperature as a result of extreme heat?

Have the elderly, overheated person lie down, and place a damp cloth on the forehead. Then after that treat them for shock. Also if they are okay enough give them something cool/cold to drink so to help them cool down there body temperature, and put them in shade. Or if near a building take them inside if you are sure you can move them carefully.