Shaving the head on a calamity is forbidden
وَقَالَ الْحَكَمُ بْنُ مُوسَى حَدَّثَنَا يَحْيَى بْنُ حَمْزَةَ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ جَابِرٍ، أَنَّ الْقَاسِمَ بْنَ مُخَيْمِرَةَ، حَدَّثَهُ قَالَ حَدَّثَنِي أَبُو بُرْدَةَ بْنُ أَبِي مُوسَى ـ رضى الله عنه ـ قَالَ وَجِعَ أَبُو مُوسَى وَجَعًا فَغُشِيَ عَلَيْهِ، وَرَأْسُهُ فِي حَجْرِ امْرَأَةٍ مِنْ أَهْلِهِ، فَلَمْ يَسْتَطِعْ أَنْ يَرُدَّ عَلَيْهَا شَيْئًا، فَلَمَّا أَفَاقَ قَالَ أَنَا بَرِيءٌ مِمَّنْ بَرِئَ مِنْهُ رَسُولُ اللَّهِ صلى الله عليه وسلم، إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم بَرِئَ مِنَ الصَّالِقَةِ وَالْحَالِقَةِ وَالشَّاقَّةِ.
Narrated Abu Burda bin Abi Musa: Abu Musa got seriously ill, fainted and could not reply to his wife while he was lying with his head in her lap. When he came to his senses, he said, "I am innocent of those, of whom Allah's Messenger (ﷺ) was innocent. Allah's Messenger (ﷺ) is innocent of a woman who cries aloud (or slaps her face) who shaves her head and who tear off her clothes (on the falling of a calamity)