Sure, if all your fans are running, heat shouldn't be an issue .. but chips typically don't run from cold for more than a minute or two without a working heat-sink / fan, so any sort of failure in that department can easily be terminal .. 
Sure, if all your fans are running, heat shouldn't be an issue .. but chips typically don't run from cold for more than a minute or two without a working heat-sink / fan, so any sort of failure in that department can easily be terminal .. 
