With the current heatwave blistering the country — and many of those affected stranded without power — most people aren't thinking about how the heat is hitting their gear. However, users of the Canon S100 have been noticing a "Lens Error" notice on their camera, and warm weather is to blame. It appears that some of the internal connections of the S100 may come loose with high temperatures and humidity. Canon has released a product advisory for the issue, describing the problem as:
Some PowerShot S100 units (with the serial numbers listed below) may encounter a lens error due to a part becoming disconnected inside the lens. In particular, this lens error may occur when the camera is used in certain environmental conditions such as high temperature and/or humidity.
If you have an S100 with a serial number that runs 29xxxxxxxxxx through 41xxxxxxxxxx, you're eligible for a free repair from Canon, regardless of warranty status, if that's found to be the cause of the issue. Contact Canon to find the best way to get your camera checked out.