C3 Brakes seizing -help!

[Ringmaster]

Hi folks!

Thought I'd take my C3 out for a spin in this lovely weather, as it hadn't been out for a couple of weeks.

I began to notice that it felt like something was holding it back. Then the brake pedal felt much firmer that I am used to. Just before I got home something seemed to go thud under the car somewhere, and all seemed back to normal.

The front discs were steaming hot. Rear discs were very hot too, but nothing like the front.
I don't think the problem has gone away.

Can both front calipers seize at the same time? They are original.

Any ideas please.....