A portion of the condenser coils on some refrigerator models has been foamed into the cabinet walls. The sides of a refrigerator or freezer with a forced air condenser underneath will be heated if the coils are not cleaned. Additionally, if the unit's ambient temperature is higher than usual, the side walls may also be warmer than average. The coils under the refrigerator will typically need to be cleaned. If the issue persists, call for assistance right away to prevent more harm.