Food poisoning comes about when dangerous (called toxic) bacteria are allowed to multiply on food we eat.

Bacteria are on all food and in the air around us. Most of them are useful or harmless. But some are not. They can easily multiply in the warm conditions of our guts and when they do they release poisonous liquids which then cause illness and sometimes death.

As a result, it is quite important that we stop these bacteria from getting inside us. Our normal guts can cope with an average amount of these bad bacteria, but not with food that contains a large amount.

So how do these bacteria multiply? Usually on food left open, and especially on warm food. Bacteria grow very quickly on warm food. This is why food that has been warmed for serving should not be cooled and warmed again. That is very likely to give food poisoning.

When we cook food at high temperatures we kill the bacteria, which is why cooking food thoroughly is the safest thing to do.