Is it safe to embrase a person who is being treated with radiation(oncology) on his head?

Embrace: Precautions for what? He or she is not infective nor are they radioactive material.

No, not really: Patients receiving radiation to the head are not in any way infectious or radioactive. They may have scalp tenderness or dry skin, but no precautions are necessary.

No: Radiation therapy is generally delivered with x-ray based treatment. This type of radiation is gone immediately after the treatment is done.

No: No worries of radiation exposure risk to others. Be careful of tenderness or dermatitis in scalp & skin but touch & TLC is a far needed treatment too!