Fiqh-us-Sunnah Volume 1, Purification and Prayer, Fiqh 1.064B.

If one is in this condition, and believes water will worsen it (he does not have to be absolutely sure, but may base his opinion on past experience or what a knowledgeable person has told him), he may perform tayammum. Jabir said, “We were on a journey and one of us got injured. Later, he had a wet dream. He asked his companions, ‘Can I perform tayammum?’ They said, ‘No, not if you have water.’ He performed ghusl and died. When they came to the Messenger of Allah, they informed him of what had transpired. He said, ‘They killed him, Allah will kill them. Do you not ask if you do not know? The rescue of the ignorant person is the question. He could have performed tayammum and dropped water on his wound or wrapped it with something and wipe over the wrapping, and wash the rest of his body.” This is related by Abu Dawud, Ibn Majah, ad-Daraqutni and Ibn as-Sakin, who said it is sahih.