So iv bled my brakes, new pads and all was ok.

However,, I went down an intensely fast hill and my brakes got hot I mean red hot,,when I got to the bottom I noticed my front brakes were not really doing g anything,, I put them on and the front wheel just span?

Any ideas??

What brakes? what fluid? Were you dragging all the way down?
Brake Fluid can boil if overheated and suffer performance loss, was the bleed good? You could just have liberated some bubbles

Bleeding is always a good place to start.

You got a leak going on? Or the wrong fluid.

If you actually got your MTB brakes RED hot, then well done, you’re seriously rad!!

More seriously, which of the following occured:

1) you were able to easily pull the brake lever to the bars without stopping the front wheel (ie, never built up any brake pressure due to boiled fluid / air in system)

OR

2) The lever pulled as normal, stopped before it hit the bars, but the front wheel didn’t stop (ie, the pistons were seized or the pads insanely glazed)

Number 2.

They were completely fine before but I hadn’t put them through that level of pressure,, it’s weird because the front stopped but then I had to re-adjust the lever to get it kind of working again.

The rear on the other hand the lever seemed to stiffen up quite a bit at the bottom.

Strange but keen to get it sorted

did you bed the new pads in? if you didnt then you may have killed the pads on that descent especially of you were dragging the brakes
the pads may be glazed or contaminated which could be due to a leak at the caliper…possibly at the bleed port