Ignition fuse blown. After replacing no further issues

Today while idling the car for about 4 minutes after a 2 hour drive, suddenly out of the blue the car switched off. After checking the fuses , i found the ignition fuse (42 i think) be the cause.
I replaced the 15amp fuse and drove for about another hour without any issues.
Pretty weird. I am with the car in france now where it is currently very very hot. about 40 degrees. I experienced some heavy rains along the way during the 900 miles trip. Aircon is blowing at its max.
The heater matrix is done a few months ago. I could not find any signs of a wet floor. Although i noticed the aircon to release quite some water occasionally.
Should i worry?

If it happens again yes, you have an issue. Carry a few spare fuses to get you out of trouble. It might not reoccur so don't worry about it.
If it does, think what you have on that could draw a current such as aircon, lights, satnav etc. Also measure what the alternator is producing in volts and when your car is off, the voltage of the battery. It might lead you to the culprit.

It’s unlikely to be the ancillary systems like AC etc, as they are seperately fused and enabled by relays.

Unless something unusual was happening when the fuse blew it is most likely a weak fuse that decided today was the day.

But, the AC should produce a steady stream of water, not big amounts for short periods. This might indicate a blocked drain and of course the heavy rain could have got somewhere it shouldn’t have. As MLC says, see how you go.