No. Like I said if it's not around my neck it's safe in my bag, which is like a GIANT case. Personally I just don't worry about that stuff but to put your mind at ease I had that Canon SLR for 5 years, and I did EVERYTHING with it, left it outside in the freezing cold, it froze, took it to the sand dunes with out a case, etc. and I never had ANY issues with it in all 5 years. I treat my equipment very well but I definitely put them through the ringer. I had it cleaned 2 in that 5 years but no, i don't, personally, worry about that. They are much more resilient then people give them credit for and you can always get them cleaned.
I know there aren't a whole lot of people that think this way :-)
Now to add onto that... OMD EM1 and EM5 are water resistant and dust proof as are a lot of the olympus lens. SOOOOO if you're concerned with that it's even more insentive to get a Olympus.