It was about six years ago and I still have the scar to prove it! Of course it was summer and I had my shorts on, swung my legs out and pulled my left leg back and hit the pipe. Instant blister ahhh the fun.
I used to have an Emmick racing go cart with the straight exhaust pipe sticking out. Made a couple of test runs down the street and my boxer touched his nose to the pipe!!!! Sizzle and he was gone.....
At least I haven't burned ny nose..LOL
Guards, covers, safety precautions, heck no! If your going to play with a cobra you are going to get bit!!!