When the refrigerator is working, the room of the refrigerator will be cooling or freezing, the heat that is absorbed from the food of refrigerator will change to the high-temperature and high-pressure gas. The gas enter to condenser and dissipate the heat through the condenser . Condenser is installed on the back or both sides of refrigerator. So when you touch the cabinet that installed the condenser, it is warm, especially in summer, it will be hot.
solution :
1.keep the refrigerator more than 10cm to the wall.
2. Keep the refrigerator in the ventilative place.
About the temperature of the sides and back of the refrigerator, the standard is:
at ambient temperature of 25 ℃ (which this standard is using as normal base) the max. temperature measured on coated metal surfaces of appliance enclosures must not pass over 85 ℃