A touch from a man consistently gets women hot under the collar, according to recent research.

Women who were touched by male scientists during an informal interaction typically became flushed around their face and chest area and their temperature was raised as much as one full degree Celsius.

Unbeknownst to the women, scientists used heat imaging equipment to study the changes in temperature during normal conversation. They found that interacting with men tended to increase a woman's temperature, while the same was not found when they were talking to another woman.

The face typically heats up during stress and scientists at the University of St. Andrews, UK, wanted to find out whether a similar reaction occurred during other emotions.

They found that a participant's average temperature would rise about a tenth of a degree when a scientist of either gender touched them. But this rise became three times as much when a male scientist touched a young female participant on the chest or the face.

"We weren't manipulating their emotional or affective state, it was a subtle social interaction with the experimenter … but they had pretty large reactions," researcher Amanda Hahn was quoted by LiveScience as saying.

Most participants said they weren't aware of their reaction to the casual touch.

Hahn and her colleagues say they hope to do further research using this non-invasive observation method in order to understand more about our physical reactions to emotions.