Plant cells are injured when temperature drops below a critical level for a species. Low temperature (e.g. chilling and freezing) injury can occur in all plants, but the mechanisms and types of damage vary considerably. Many fruit, vegetable and ornamental crops of tropical origin experience physiological damage when subjected to temperatures below about +12.5 °C, hence well above freezing temperatures. However, damage above 0 °C is chilling injury rather than freeze injury. 

Chilling injury is damage to plant parts caused by temperatures above the freezing point (32°F, 0°C). Plants of tropical or subtropical origin are most susceptible. Chilling-injured leaves may become purple or reddish and in some cases wilt. Both flowers and fruit of sensitive species can be injured.

Chilling injury (reddish color) on leaves of Princess Flower (Tibouchina urvilleana)