I just got my first iPhone. One way I justified the additonal expense of a smartphone was that I plan on mounting it to my bike and using it as a GPS cycling computer.

I have my iPhone in an Otterbox Defender case. However, I removed the plastic screen cover that came with the Otterbox because I already have an Invisible Shield screen cover installed on my phone. I plan to order a bike mount that is compatible with the Otterbox so I can mount the thing on my stem.

When I have the iPhone mounted on stem, do I need to worry about protecting it from sweat, or is this not a problem to worry about? I do not ride in rain or adverse weather, so the main source of moisture would be sweat and saliva.

Just curious in general what precautions people take when mounting a smartphone on a bike.