It's bad enough that they suffer second-degree burns at the drop of a sunhat and hurt feelings from a barrage of barbs aimed at their fiery heads. Now it seems nature might have added injury to the insults heaped on redheads, by making them extra sensitive to physical pain.

Researchers at Southampton University Hospital are carrying out trials this year to discover whether pale-skinned patients who share their hair colour with Elizabeth I may require more anaesthetic than the rest of the population. The results should either confirm or disprove previous research in the United States suggesting that redheads are indeed more susceptible to pain.

Red hair results from variants of a gene that plays a key role in human hair and skin colour. The same gene is involved in the production of endorphins, the body's natural painkillers. The Southampton study aims to find out whether this could explain redheads' apparently heightened sensitivity.

In the trials, due to end in September, volunteers aged over 30 with red hair are anaesthetised and subjected to electrical charges through their thigh. Their reactions will be compared with those of a group of men and women with brown or black hair.

If it turns out that red-haired people do feel more pain, it will help to explain previous research showing they are more fearful than other groups about visiting the dentist. An American study found that redheads were more anxious about dental treatment and more than twice as likely to avoid it. A second study by the same researchers found that women with red hair needed 19 per cent more painkiller to stop them flinching from unpleasant stimulation than women with dark hair. "Redheads experience more pain from a given stimulus and therefore require more anaesthesia to alleviate that pain," said Dr Edwin Liem, who led the study at Louisville University.

This is just one of many burdens the flame-haired have had to bear over the ages. In ancient Egypt carrot-tops were buried alive; today they are routinely blamed for everything from bad weather to soured milk.

If the Southampton study shows that redheads really are more prone to pain it will go some way to explain why they might be fiery and hot-tempered: they're not being difficult, they're just hurt.

Red propaganda: Myths and legends of the flame-haired

Three per cent of people in the UK have red hair.

Thirteen per cent of Scots are redheads, more than anywhere else.

Redhead genes are thought to date back 20,000 to 40,000 years.

Gingers don't turn grey. Their hair becomes sandy and then white.

Legend states that King Arthur had red hair.

It was once symbolic of a raging libido: "red on the head, fire in the bed".

Bees are thought to sting redheads more than others.

Liverpool folklore states that meeting a redhead at the beginning of a journey is a bad omen.

The colour was considered to be untrustworthy; Judas is often depicted as a redhead.

Greeks believed that redheads turned into vampires after death.