Just be careful when you are ironing cotton fabric with iron on cotton setting; move  your iron quickly. 

My wool felt pad now has a few brown scorch marks.  Nothing drastic but I guess those marks show I am slowing down in my old age.

if you use steam be careful tho, I've had steam go through my thick one.  I'm guessing it would go thru a thin one quickly.

You are so right, Dee!  I used my mat on the kitchen table, and when I quit for the day, there was a fair amount of condensation under the mat.  I really could have warped the table surface if I had left it there longer. 

Sue in IL