This video is a proof.
The woman in the video attempted an ice bucket challenge by sitting atop a horse. But as soon as she poured a bucket of ice-cold water over her head, the animal panicked at the touches of the cold water on its back and started running. The woman could not meet the challenge of taming the horse and she fell down as the animal ran a few steps.
In the game of ice bucket challenge, the nominated participants get themselves filmed while having a bucket of ice water poured on their heads. The rule is that nominated people have 24 hours to comply or escape by donating $100 to the ALS association.