Founder is also my guess - big time founder if the hooves are hot.
If you can ice pack their hooves, do that. If not, put the cold water hose to their hooves, about 15 minutes each hoof.
Soaking foundered hooves in cold water isn't the first line of defense anymore but, if they won't let you pack them in ice, you've got no choice.
while you're standing there doing all that, get the cell phone out and call the farrier AND the vet "five minutes ago".
As others have stated, this nothing to mess with or leave go.
And by all means take away their grain. Just give them grass hay, NO alfalfa. Soak their hay for now, until the vet can give you instructions.
Unless they got into the grain bin, they have foundered on Fall grass which is every bit as dangerous as spring grass <---even if it's brown, the roots are alive and forcing sugars up the ground on warm days.