Reheating a takeaway (or if you’reAmerican, take-out) may seem like a good idea at the end of a hard day – butmany of us have learnt that there can be a heavy price to pay. Around onemillion people in the UK suffer food poisoning each year, and it’s oftenbecause we have failed to take a few simple steps.

Michael Mosley of the TV programme Trust MeI’m a Doctor uses a thermal camera to analyse whether reheatedtakeaway food is safe or not.

As Mosley explains, the trick is to heatthe food until it is 82C (176F) throughout to be sure that you can kill anyharmful bacteria.

That’s easier said thandone: while the outside may seem to be steaming, the inside could have remainedcooler –hosting a pocket of living bacteria. It’s for thisreason that it’s important to stir the dish so that all the food is heated evenly.

Even after having followed these steps, youshouldn’t reheat a meal more than once. Each time it cools down, you offer moreopportunities for the harmful bacteria to multiply, making it harder to killthem all off the next time you stick them in the oven or microwave.

This is particularly true for oneparticular takeaway favourite – rice – which can host spores of a nasty bugcalled Bacillus cereus. When left in food, the bacteria produces toxins thattrigger diarrhoea and vomiting. Unfortunately, these toxins are “heat stable”meaningthat even if you heat the rice to the point of killing all the bacteria, thetoxins will survive –and you’ll soon notice the effects of ingesting those poisons.

If you do want to save your leftovers, youshould cool the rice quickly – before the bacteria can start churning out thosetoxins – and refrigerate within an hour of cooking. Otherwise you really are“playing Russian roulette with your guts”, says Mosley.