Nah --- just resting

What you smilingly reply if a concerned passerby stops next to where you're exhaustedly sprawled out beside da road and asks if you need help.

Motorist, slowing down next to where a pedestrian is lying flat on da sidewalk: You sick or hurt, Buddy??
Pedestrian, giving a casual and appreciative flutter of his hand: Nah --- just resting --- thanks for stopping to check on me, anyway, though!