Multimeter resistance measure
Your multimeter will be fine. It will display that the resistance is infinite if the resistance is greater than the range. 
The reason you don't have to worry is because the multimeter is acting a constant current source, a very small one. So even if you short the probes, there will only be a small current flowing through them. 
Since it is a constant current source, it can measure the voltage across the probes as well. R = V/I, we know how much current we are pushing through the resistor and we are measuring the voltage across the resistor, therefore the multimeter knows the resistance.
That is how the resistance function of a conventional multimeter works.