pg 110 org made easy writes temperature is needed for Esub of
halogen into benzene and methylbenzene.
chankimseng's is room temp for all
http://www.chemguide.co.uk/organicprops/arenes/halogenation.html
also writes r.t.
You've already done your own research into 3 sources, and can come
to your own conclusion. My help is not needed here. Learn to be
independent. Little things you can make your own decision, no need
to ask me.
(Fyi, in this particular case, as long as you did include the
Lewis acid catalyst, Cambridge will accept either version, as using
a little bit of heat to increase the rate of reaction does not
result in disastrous side reactions and hence will not negate the
mark, unlike say, if you included UV light.)