It might vary, depending on multimeter.
But if on a multimeter, there is printed "10A for 30sec. MAX every 15 min" or "20A for 15 sec (time unspecified)", below which approximate threshold is the safe duration of measurement indefinite?
Here's an approximation. The answer is probably too low.
30 sec every 15 min is a 1/30 duty cycle. So assume 10A dissipates 30 times what the meter can handle continuously.
Power dissipated in a resistor is proportional to current squared.
So we would get the same average power with a current of 10 (1 / √30) amps = 1.8A