Different countries in Europe have vastly different electrification systems. Most use either 25 000 V AC or 3 000 V DC, but then there's the 15 000 V AC used by German-speaking countries, Sweden, and Norway. And the French-Dutch 1500 V DC.
And France uses 25 000 V on all of its new lines as well.
Electricity can jump about 1 cm per 1 000 V, so Finnish 25 kV overhead wires can shock you at a distance of 25 cm, south-French 1.5 kV overhead wires need you to be under 1.5 cm away from the line.
Converting to inches and feet: 1.5 kV needs you to be closer than an inch to the overhead wire in order to get electrocuted, while 25 kV can jump almost a foot.
It happens regularly that young people die when they climb atop freight wagons and get too close to the sstructures holding the overhead line. They only know to avoid the line itself, but don't understand how.far electricity can jump nor that it's not only the wire that is "hot", but also all structures up to the isolator.