As stifling heat waves continue to bear down on much of the United States, many workers are feeling a different type of burnout this summer.

CareerBuilder's recent survey on employee productivity found that one-in-four employers (26 percent) think workers are less productive in the summer and nearly half (45 percent) think workers at their organization are currently burned out on their jobs. The national survey was conducted May 19 to June 8, 2011, and included more than 2,600 hiring managers and human resource professionals and nearly 5,300 employees.

Nicer weather, vacation-fever, and kids being out of school led the list of reasons for the perceived summer productivity dip.

Looking at overall productivity trends year-round, 30 percent of employers say workers are more productive today than before the recession began; 12 percent feel workers are less productive than before the recession.

Employers who saw a rise in worker productivity during the recession primarily attribute the increase to the fear of losing a job and the effects of downsized staffs on individual workloads. In addition, 73 percent are seeing the increase sustain today and 14 percent state productivity has increased even more.

"The recession produced consequences for not just those who were laid off, but also for the many employees who were asked to work harder as a result of leaner staffs," said Brent Rasmussen, president of CareerBuilder North America. "While getting more out of a smaller workforce is a sign of organizational agility during unpredictable times, it's hard to see such yields in productivity holding forever. Headcount will be needed to meet increasing demands."

Worker Burnout

When looking at burnout from the worker's perspective, employers have cause for concern. 77 percent of workers say they are sometimes or always burned out in their jobs and 43 percent of workers say their stress levels on the job have increased over the last six months.

The rising stress could be a result of heavier workloads. Nearly half (46 percent) of employees reported an increase in their workloads in the last six months, while only eight percent said their workloads decreased.

Survey Methodology

This survey was conducted online within the U.S. by Harris Interactive© on behalf of CareerBuilder among 2,662 U.S. hiring managers (non-government) and 5,299 U.S. workers between May 19 and June 8, 2011 (percentages for some questions are based on a subset, based on their responses to certain questions). With pure probability samples of 2,662 and 5,299, one could say with a 95 percent probability that the overall results have a sampling error of +/- 1.90 and +/- 1.35 percentage points, respectively. Sampling error for data from sub-samples is higher and varies.