Software developers work on a variety of tasks ranging from the technical, e.g., writing code, to the social, e.g., participating in issue resolution discussions. The amount of work developers perform per week (their work-rate) also varies and depends on project needs and developer schedules. Prior work has shown that while moderate levels of increased technical work and multitasking lead to higher productivity, beyond a certain threshold, they can lead to lowered performance. Here, we study how increases in the short-term work-rate along both the technical and social dimensions are associated with changes in developers' work patterns, in particular communication sentiment, technical productivity, and social productivity. We surveyed active and prolific developers on GitHub to understand the causes and impacts of increased work-rates. Guided by the responses, we developed regression models to study how communication and committing patterns change with increased work-rates and fit those models to large-scale data gathered from traces left by thousands of GitHub developers. From our survey and models, we find that most developers do experience work-rate-increase-related changes in behavior. Most notably, our models show that there is a sizable effect when developers comment much more than their average: the negative sentiment in their comments increases, suggesting an increased level of stress. Our models also show that committing patterns do not change with increased commenting, and vice versa, suggesting that technical and social activities tend not to be multitasked.