Insultation can melt in poorly installed outdoor electrical fittings, leading to a short circuit. You might then have to change your entire distribution board. 

Because of the risk of exposure to water, outdoor sockets should have a circuit breaker. Without this you are risking electric shocks and fire. 

Sockets, light switches and other electric installations in wet environments can be risky. If you are planning a bathroom or kitchen renovation, make sure a qualified electrician inspects the wiring.