I wonder, does your HVAC system work without power? Considering that any electric grid might just collapse when everyone flips on their air conditioning in 49 °C heat?
It's not just increased demand. The typical power generator is a heat engine and an important part of heat engines is cooling. In the case of electric power generation you need to condense the steam back to water. You need water below a certain temperature in order to do that. If your river or lake gets too hot - you have to shut the unit down.