Want to avoid getting sick this winter?Minor facial changes in sick people can signal if they're under the weather, according to research led by Swedish psychologist John Axelsson of the Karolinska Institute."We can detect subtle cues related to the skin, eyes and mouth," said Axelsson. "And we judge people as sick by those cues."A person's face is the biggest giveaway as to how he or she is feeling, and some people even have a "sickness radar" that can detect illness in others."This supports the notion that humans have the ability to detect signs of illness in an early phase after exposure to infectious stimuli," scientists said.