The Haze glitch is a natural glitch which occurs in Pokémon Red, Blue, Yellow.
In Generation I and II, the move Haze thaws out the opponent and removes the effects of Confusion, the stat reductions from Burns and Paralysis, the effects of Leech Seed and the cumulative stage of Poison, in addition to neutralising all stat changes.
There is a glitch in Pokémon Red, Blue, Yellow where if Haze thaws out a frozen Pokémon on a turn when the frozen Pokémon must recharge from Hyper Beam, it will remove the Freeze status but the Pokémon cannot make a move until it faints, even if hit with a Fire type move which was the only way (except for Haze/Ice Heal/Full Heal/fainting) for a Pokémon to thaw out in Generation I.
This glitch is similar to the Sky Drop glitch in Pokémon Black and White and Pokémon Black 2 and White 2. It was one of several glitches fixed in Pokémon Stadium.