Pre-cooling is the first step in good temperature management. Rapid pre-cooling to the product's lowest safe temperature is the most critical for crops with high respiration rates. But it is helpful for almost all. Most crops are harvested under relatively mild or warm weather conditions, at times temperatures can reach 40 ℃ or more. Respiration rates for typical crops will be twice as high for every 5 ℃ above 0 ℃. This means four times the rate at 10 ℃ , 8 times at 15 ℃ , etc. It is easy to see then how dramatic the detrimental effect of high temperature can be.

As a example, fresh berries such an blackberries, strawberries, and blueberries are very perishable and require immediate cooling after harvest to prevent a rapid decline in quality. At warm temperatures (<30 ℃), softening and decay can occur in less than four hours. Proper cooling and handling of strawberries can extend the shelf-life to 10 days or more.

The field heat should be removed as quickly as possible before shipping, processing, or storage. To prevent damage to already harvested and stored crops, pre-cooling must be a separate operation from storage or shipping - specialized equipment is required.

Temperature is the single most important factor in maintaining quality after harvest. Refrigerated storage retards the following elements of deterioration in perishable crops:

●　respiratory heat production accelerated ripening and rapid decay, undesirable
　　softening of tissue, and textural and color changes
●　respiratory heat production leading to undesirable metabolic changes affecting nutrition and
　　flavor
●　decrease in marketability due to poor appearance and a result of moisture loss and the
　　wilting
●　moisture loss also leads to reduced economic return when sales are based on weight
●　increased waste and customer claims as produce suffers invasion by bacteria, fungi, and
　　yeasts; undesirable growth as in curvature of asparagus and flowering of broccoli