Mix sugars, peanut butter, and shortening. Add baking soda to the hot water. Add to mixture. Stir well.
Stir in the eggs. Add the flour. Roll dough into balls.
Place balls on ungreased cookie sheet. Press with fork dipped in water to make criss-cross design. Bake at 350 - 375 degrees F (175 - 190 degrees C) for about 8-10 minutes.