What are the risks of power supply from the network 220?

Question

Batteries

I have a laptop, a phone and a small hair dryer (500 W) when I travel. They are usually connected through an extension cord for 4 outlets.
What can go "wrong" in the network, which will lead to the failure of the extension cord, charger or hair dryer?
What can go wrong in an outlet next to a laptop, causing it to break?
(I would like to understand the list of risks and how to protect yourself from them).

Answer 1

Carry a voltage control relay with you, about 200g of weight. (for example , see google , or choose another model for response time = smaller)
And you don’t need any stabilizers and UPS, as they suggest :)

Answer 2

Carry a stabilizer with you (well, or a UPS)