When the outside temperatures rise, people tend to lose their cool. That connection is well known, but a new study found that emotional responses to heat are highly individualized and only one factor moderated it -- age. Overall, researchers found that the actual temperature at which the majority of people felt uncomfortable during a hot summer depended on the individual. When they did feel discomfort, it often negatively affected their mood. The exception: older adults on average became more uncomfortable in high heat more quickly, but it did not affect their mood as much as it did younger adults.