A couple two three things comes to mind here!
1) WHY?
2) I've seen wider tires on a 10 speed bicycle!
3) The heat is freaking intense it must be HELL riding on a summer day and the radiant heat that rises must be incredible! Anyone that's ridden has had their leg at one time or another make contact with the exhaust pipe. With pants on not so bad with shorts I've seen plenty leave a hunk of hairy skin on a straight pipe in my life!
With this I could see a pair of jeans with a mere touch spontaneously incinerate into some serious hot pants!