Yes, I wear the Shift Racing Enforcer Knee/Shin Guards for $13 plus shipping (I got mine at a motorcycle shop for about $20).
I wear mine year round, under my nylon pants.
One review- “I wear these under jeans when the weather is hot. I was using a set of shin/knee guards from Fly Racing, but they were not vented. These allow air to pass through, making them much more comfortable.”