I wouldnt have thought there is much risk of "catching "something. As far as I am aware, ambient temperatures soon kill bugs that like the 37 deg C of our bodies
but not cooler temp.
On a lower note, I was always told that it was impossible to catch VD from a lavatory seat for the same reason, so don't use that as an excuse!!
I reckon a good dose of alcohol would be more than enough to make double sure>
