Dr Alastair Ritchie of the Bioengineering… The next time you suspect you are overdoing things mentally, a quick check of your nose temperature could prove illuminating. Scientists have discovered that a cold hooter is a sign of thinking too hard. In a new study, in which researchers used thermal imaging cameras on the faces of 14 volunteers while they carried out mental tasks, they found that the nose temperature of those feeling overwhelmed dropped by around one degree centigrade. The scientists say it as a sign that the brain is overworking, and has ordered that blood should be diverted to help neurons. Extremities, like the nose, suffer first because it take more energy to pump blood to them.