First things first:

DO NOT attempt to touch the brake discs after you have been braking. Brakes work by converting your cars kinetic energy to heat energy and then disipating it to atmosphere. So you would expect them to be too hot to touch after braking.

However, if they are creating this much heat in such a short distance, then it does sound like you have a sticking caliper on that brake. You should seek a second opinion from a trusted independant garage, but this time ask for advice based on an inspection.

Woryingly, you seem to indicate that both front brakes are exhibiting the same issue. I would be surprised if both calipers are faulty, but it is by no mean impossible, so again inspection is the key.

You could try going to your local independant MoT station and ask them to conduct a brake test on the rollers. One of the tests is for rolling resistance so they will be able to tell you if the results do in fact appear high. My own Saab 9-3 has about 14Kg resistance on each front wheel (front wheel drive so this includes gearbox drag). The tester will have experience of the sort of figure your type of vehicle should give.

Other points:
When you say "garage" which garage are you refering to ? The garage that sold you the vehicle? Or somewhere else?
Is the vehicle new or did you buy it used? If the latter, how old, what mileage?
Whoever this garage is, did they give you this advice in writing or do you have any other record?
I would phone the garage from my mobile with my call recording app active and get them to repeat their advice - but advise them they are being recorded right at the beginning of the call (in other words, to whatever secretary answers, but do not repeat the warning to whomever she passes you to to discuss the issue - get my drift?)
As you are recording the call, once they've reiterated their advice, let them know that you will be seeking a second opinion and if any repairs are needed you will hold them financially responsible. Back this up in writing (recorded mail or email). I'm assuming we are talking about a garage that sold the vehicle used and that they are fobbing you off (and that you have actually got a problem).

You know what to do next.