We're midway through summer and one side of your brain may be thinking about the beach. Or the pool. Or the park. Anything but the cubicle.

Summertime usually means lots of sun and outdoor fun. Unfortunately, even when working 9 to 5 indoors, the combination of high heat and high humidity can inhibit worker productivity, reaction times and ability to focus.

"A performance study by NASA using telegraph key operators showed that in temperatures of 80°F, the operator will make five errors an hour and 19 mistakes after 3 hours," EHS Today noted last month. "At 90°F, the operators made nine mistakes per hour and 27 after 3 hours. At 95°F, the mistakes went to 60 in 1 hour and 138 in 3 hours.

"Although errors made by telegraph key operators may not be critical, this same hot environment will produce a proportional amount of errors regardless of the task," the health and safety publication said.

A CareerBuilder.com survey of 4,285 full-time U.S. workers found that 22 percent claim a too-hot workplace makes it difficult to concentrate. Although the U.S. Occupational Safety and Health Administration does not have regulations that address temperature and humidity in an office setting, a subsection of the technical manual recommends workplace temperatures ranging from 68 degrees to 76°F and humidity ranging from 20 percent to 60 percent. (Source: Society for Human Resource Management)

Here are some tips for fighting summer productivity lethargy.

Use a desk fan. Start by investing in a desk fan if you don't already have one and ensure it's in good condition if you do. Small fans not only reduce heat buildup and circulate air, they reduce air-conditioning costs and often provide a more comfortable (less noisy) space in which to work. Heed this warning from the Centers for Disease Control and Prevention: "Electric fans may provide comfort, but when the temperature is in the high 90s, fans will not prevent heat-related illness."

Dress appropriately. It's hard to look neat and professional when your button-up is drenched with sweat. "Even if you take off your suit jacket, the shirt underneath it is plastered to your sweaty back before you board your train," Kate Lorenz of CareerBuilder.com writes. Revise your summer work wardrobe. Wear loose fitting and comfortable clothing, especially clothes made from non-synthetic material that won't hold in heat, such as cotton. Loosen ties and buttons around collars. However, before you replace Oxfords with sandals and dresses with tank tops, consult your company's dress code.

Do important tasks first. Take care of important or difficult tasks before you get hit by the afternoon slump caused by lunch — when the body's resources are suddenly diverted into digesting a meal — or the hot midday sun. Not only does this offer you a window during which you'll be less distracted (fewer coworkers, fewer phone calls, less outside heat), but it also keeps you from "feeling guilty when you totally zone out in the afternoon," as Erin Doland, author of Unclutter Your Life in One Week, writes at Unclutterer.com.

Adjust your work schedule if possible. The temperature may fluctuate throughout the day, making some hours more bearable than others. "If temperature is a concern, workers and employers can easily work together to find common ground so productivity does not suffer," Rosemary Haefner, vice president of human resources for CareerBuilder, says. If a particular time of day or office space is too warm for productive work, talk to your manager about adjusting your work schedule, telecommuting or moving to a conference room for a portion of the day.

Keep those fluids going. Drink plenty of fluids throughout the day, and be smart about what you drink. Keep a water bottle handy all day, and don't wait until you feel thirsty to take a sip. A 1988 study concluded that even a 2 percent dehydration level caused by heat stress can dramatically reduce a worker's reaction times and ability to focus. "Your brain is mostly water, so it makes sense that you'd need to keep yourself hydrated for maximum alertness and productivity!" Stepcase Lifehack says.

Avoid heavy lunches. Try to avoid hot and spicy snacks, and opt for cooler and lighter foods and salads at lunchtime. "If the meal is hard to digest, it often puts me right to sleep or into a zone," Doland writes. "Lighter lunches don't seem to have the same impact." Rediff News recommends lunches containing protein and dietary fiber, adding lean meat, poultry, nuts or beans to a salad or eating sandwiches with 100 percent whole grain bread or a whole-wheat tortilla.

Take breaks throughout the day. "If you are working in an office, take plenty of breaks and if possible, get up and walk around even if it's only for a few minutes," Article Alley, a user-generated content resource, advises. "It's easy whilst working to forget your immediate surroundings and the effects of the heat can suddenly creep up on you."

Enjoy your free time. The constant push for productivity in today's economic environment can make people take their time outside work for granted. The problem is amplified by people feeling pressured to work longer and produce more to protect their jobs. If a week-long, get-away-from-it-all vacation this summer is nothing more than a romantic notion, remind yourself why you work. Having a family and friends and a job is OK, so fight the guilt. When you leave work at the end of the day, take advantage of — and enjoy — your free time.

A hotter-than-normal workplace can lead to lethargic, less-productive workers, but that's not the worst of it: excess heat is one the most frequent causes of workplace injuries and fatalities. During especially balmy summer months, employee safety and health concerns must not be ignored.

Do you have your own tips for staying productive during the summer? Let us know in the comments section below.

Resources

How Heat Stress Affects Performance
by Bruce Baker and John Ladue
EHS Today, June 1, 2010

One-Third of Workers Say Office Temperature Affects Their Productivity...
CareerBuilder.com, Dec. 15, 2009

Too Hot! Too Cold! Temperature Affects Productivity
Society for Human resource Management, Jan. 4, 2010

Extreme Heat: A Prevention Guide to Promote Your Personal Health and Safety
Centers for Disease Control and Prevention, July 31, 2009 (last updated)

Business Casual Tips for Summer
by Kate Lorenz
CareerBuilder.com, Sept. 24, 2007 (last updated)

Fighting the Summer Productivity Blahs
by Erin Doland
Unclutterer.com, July 15, 2010

Role of Dehydration in Heat Stress-Induced Variations in Mental Performance
by P.M. Gopinathan, G. Pichan and V.M. Sharma
Arch Environ Health, 1988

7 Caffeine-Free Ways to Increase Alertness
by Seth Simonds
Stepcase Lifehack, April 19, 2010

How to Fight that Post-Lunch Slump
by Kanchan Maslekar
Rediff News, Sept. 8, 2006

Three Easy Steps for Increased Summer Productivity
by Mike Tennant
EQUICKTIPS.com, June 15, 2010

11 Ways to be Productive When You're Brain Dead
by Steve Tobak
BNET, July 1, 2010

Increase Summer Productivity in the Office
Article Alley, June 20, 2008