The Lajnah ad-Da’imah was asked the following question:
Some people, especially in the summer, shave their heads with no Shar`y (Islamic legal) excuse. Those who shave their heads offer the extreme heat and habit as an excuse for their act, knowing that shaving the head is one of the attributes of people following Bid`ahs (innovations in religion) including Khawarij (separatist group that believes committing a major sin amounts to disbelief), may Allah curse them. So what is your good advice for them?
It is permissible for a man to shave his head, especially when necessary. The Messenger (peace be upon him) granted his permission to do this, and he said to the person who left tufts of hair after shaving his head: Have your hair all shaved or leave it without shaving.(Related by Ahmad) Moreover, he (peace be upon him) ordered the mother of the children of Ja`far ibn Abu Talib (may Allah be pleased with him) to shave his children’s heads when it was necessary.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.
The Permanent Committee for Scholarly Research and Ifta’
AbdulFattaah Bin Uthman