Question: how to evolve eevee into glaceon in fire red?
Answer: Evolve Eevee into Leafeon or Glaceon by leveling near the correct Rock. In Generation 4 (Diamond, Pearl, and Platinum) and later you can find Moss Rocks (Leafeon) and Ice Rocks (Glaceon) at certain locations in the world. Level up your Eevee in the same area as one of these rocks to start the evolution.