From the time the product is initially cooled it should remain cooled. Refrigerated shipping trucks deliver produce to the retailer cold, and it is the retailer’s job to keep it that way till it leaves with the customer. Temperature fluctuations can have detrimental effects on fresh produce, causing increased respiration rates, moisture loss, and microbial activity. Leafy greens should be held at approximately zero degrees Celsius and 95% relative humidity at all times.