Clean the coils before the heat arrives
A refrigerator sheds heat through its condenser coils. Dust, pet hair, and kitchen grease insulate them, so the compressor runs longer and hotter with every degree the house warms up. Brush and vacuum the coils in May and the fridge coasts through August.
Give it breathing room
Fridges pushed tight against walls and cabinets cannot move air across those coils. A couple of inches behind and above the unit is cheap insurance, and it costs nothing.
Check the seals while it is still spring
The dollar-bill test: close the door on a bill and pull. A seal that lets it slide out freely in several spots is leaking cold air around the clock, and the leak gets expensive when the kitchen is 80 degrees.
Set real temperatures
37°F for the fridge, 0°F for the freezer. Colder settings do not preserve food better; they just work the compressor harder. A cheap thermometer tells you the truth the dial does not.
Do not panic-load a warm fridge
After a power outage or a big grocery run, give the unit time. If temperatures have not recovered in 24 hours, or the motor never cycles off, that is a service call, not a settings problem.