If he is in military or public service uniform, he salutes.
Civilians and the above in civilian dress remove hats, and hold them over their hearts. No hats, hand over heart.
That is how it is done. I believe it is part of the Federal code, if I remember correctly from training.
Yes, if you fail to remove headgear, people will mention it in a disparaging manner (in my experience).
I would mention it if I saw it, cancer patient or not. It is disrespectful to those who fought and died for the flag and the country it represents.
Moderator - Prostate Cancer(Not a medical professional)
My adjuvant IGRT journey (2010) - www.healingwell.com/community/default.aspx?f=35&m=1756808
HT (Lupron) 6-mo injection 9/12, 6/14, 12/14 (no more vacations), 7/15
Prolia 6-mo inj 12/12, 06/13, 12/13, 6/14, 12/14, 6/15
Casodex started 12/14, end 3/15/15 after psa 30% rise