Ok when this happens on these Samsung side by side what it is will be a blocked evaporator and fan.
You need to empty the fridge section completey.
Then look at the back panel in the bottom half. You may see ice/ frost coming through the vents there.
You need to remove this panel.
Remove water bottle and then the screws at the bottom of the panel.
Then remove the vents towards the top as they are clipped in and remove the screws in there.
Then remove the center panel running up the back of the fridge inside were the lights are.
Now you can remove the rear panel. If its iced up it can be a bit hard but it will come off.
Then use a hairdryer and defrost the ice in there.
Then clear the ice that will be around the fan on the back panel.
Once the ice is all defrosted refit the panels and retry the appliance and this should sort the fault out.
But if you don't want to remove panels then you need to empty the appliance and turn it off and leave the door open for 24 hours. But this way you will lose the freezer as well.
Then once its defrosted fingers crossed this will cure it. Its quite a common fault on these samsungs as ive seen it loads of times.
If after the defrost it works but say 3 weeks later it does the same then the fault is on the defrost side. Either the defrost heater or thermal cut out may be at fault.
If you need anymore info just get back to me.