Light smoke when engine runs warm

What is your question?

I have noticed that on two occasions, wispy trails of smoke wafting from both sides of the car. The second time it happened, I was in heavy traffic on the freeway. This afternoon, when I returned to my home, I could smell the acrid stench of burning, although there were no visible signs of burning. Shoudl I be concerned, and what precautions need I take? Thank you.