Starve A Fever and Feed A Cold
EDP column by Dr Ketan Dhatariya

“Is it true you should starve a fever and feed a cold?"

The simple answer to this old wives tale is no, it is not true. It probably arose from people not having much of an appetite when they have a fever but retaining their appetite if you have a cold.

The normal body temperature is about 98.4oF. There are lots of mechanisms in your body to help maintain your body temperature. The heat comes from a variety of sources – when sugars and fats are metabolised, much of the energy generated goes into making sure that the many processes that keep us alive progress at a steady rate. Part of the energy generated goes into keeping us warm. Many of the processes in our body have evolved to work most efficiently at our body temperature.

When we get an infection then our immune system comes into play. Our infection fighting blood cells (the ‘white’ cells) increase in number to help keep the infection at bay, and also to eventually kill off the bugs causing the infection. However, the white cells like the temperature a little higher that normal body temperature to keep them working at their best – they normally produce a chemical that tells the part of the brain that controls temperature that they’d like it a little warmer, and so the body heats up. This allows the white cells to work more efficiently at overcoming the infection. Once the organisms causing the infection have gone, the numbers of white cells drop, they send less of the signal to the brain and the body cools down. So in some respects it is useful to have a temperature when you are not well.

However, as we all know, having a temperature can be uncomfortable and make us feel quite ill. If your temperature is very high, then it is usually safe to take some medicines to help. Many commonly prescribed pain killers also have temperature lowering effects – such as paracetamol and ibuprofen. It may be worth trying these medications first to see if you feel better, and to help your temperature come down. However, if your temperature does not come down, or you feel worse – and especially if it is a child (babies and young children do not have the same mechanisms to deal with high temperatures) it is a good idea to see your doctor or pharmacist to see if you need any antibiotics.