Researchers from the University of Sussex have discovered that our noses get colder by as much as 3–6°C during acute stress. Using thermal imaging cameras, 29 volunteers took part in a controlled stress test, which involved unexpected public speaking and mental arithmetic challenges. This phenomenon – dubbed the ‘nasal dip’ occurs because stress redirects blood flow away from the nose toward the eyes and ears, as part of an evolutionary ‘fight or flight’ response that prepares us to look and listen for danger.

Traditionally, psychologists have relied on self-report measures like questionnaires and interviews to assess stress. However, these methods are both retrospective and subjective – participants report their stress after the event and may not always recall or interpret their experience accurately.

What makes this new thermal imaging research so exciting is that it allows stress to be measured objectively and in real time. It also opens doors to measuring stress in individuals who cannot communicate verbally, such as babies or non-human primates. In fact, the Sussex team has already used the technique in ape sanctuaries, where they discovered that watching videos of baby chimps caused rescued chimpanzees’ noses to warm up – a potential sign of reduced stress.

Beyond this, researchers believe that measuring the recovery time from the nasal dip could help identify early risk factors for anxiety and depression, offering a new, non-invasive way to understand and support mental health.

Reference: Your nose gets colder when you're stressed. These thermal images show the change https://www.bbc.co.uk/news/art... (accessed 15.10.25)

ANSWER THE QUESTIONS

1. Identify the experimental method used in this study.
2. The researchers used a controlled stress test with specific tasks (speech-giving and mental arithmetic). Why is it important that all participants experience the same standardised stressors
3. The article states that thermal imaging provides an ‘objective measure’ of stress compared to self-report methods. Explain one advantage and one disadvantage of using thermal imaging rather than questionnaires to measure stress.
4. One participant out of 29 asked to leave the study during the stressful tasks. Identify two ethical guidelines that the researchers must have followed when conducting this stress-inducing research and explain why each is important in this study.
5. Before the stress test began, participants were asked to ‘sit, relax and listen to white noise through headphones’. Why would the researchers want to establish a baseline (starting point) temperature for each participant's nose before introducing the stressful tasks.

CHALLENGE: What practical applications might this study have?