5°C to 60°C has been specified as the food temperature danger zone. This is the range in which micro-biological growth can occur quickly. If food is left too long within this temperature range then potentially deadly micro-organisms can grow.
Heating food above 60°C will kill most micro-organisms. It will not, however, remove the toxins that may have been introduced. Cooling food to below 5°C will almost stop the growth of micro-organisms.