As Salamander says, if you have a binding disc brake, caused by a sticky piston or siezure of the "floating" mechanism of the caliper, you usually can't touch the disc, it's very hot.
I have had this problem on several cars over the last few years,(but not on my RVR).
It usually announces itself by a slight judder through the steering wheel whilst driving along, but I have found this dissapears whilst braking.
To check if it is a sticky piston, I drive gently for a few miles without braking a lot, then come to a stop, again without braking much.
Immediatley carefully test the temperature of the discs with your finger, they should be slightly warm & at the same temperature.
If not you have a problem.
I find this usually happens to me when the car starts getting old, say after about 6 or 7 years, but I think it is not helped by the way I drive, very gently (I hardly ever have to replace brake pads). More "violent" driving is perhaps better at keeping the pistons free??
So every second year, at the annual service/MOT, I ensure my garage checks the pistons can be pushed back ok.
When I bought my 1995 RVR a few months ago, I had the garage do this check & all was well, but my guess is that as yours has been stood around for a while this has caused a piston to stick.