If you have to take something afterwards,
acetaminophen is better because it doesn't
alter your immune response. Painkillers
that you use for inflammation constrain the
immune response and so are antithetical to
what you are trying to achieve with the vaccine.
If your doctor insists that you have to take them
(for instance, for migraines), then, yes, but otherwise,
use cool washcloths - and if none of your washcloths are cool,
then a square one will do fine.