Q. I have heard that in cases of injury tayammum would be valid….

A. In the case of a serious injury wherein life and limb remain in danger of being lost, tayamum alone would suffice. A mere increase in flu like symptoms, etc. would not permit tayamun of the entire body or entire limb. If reference is made to the head injury suffered by a sahabi — a case in wherein other sahaba made him fully wash-up causing the injury to get worse resulting in his death. In the sahabies case, and similar cases, if such a serious situation applies, tayamum would be allowed and more virtuous then washing the body or its portions that would cause greater harm.

May Allah bless you with a speedy recovery, Ameen.

Allah Certainly Knows Best.