According to the U.S. Dept. of Labor, about 8 million Americans work second jobs to make ends meet or pay debt and save money faster. Are you included? If so, beware, because moonlighting takes its toll. It’s mentally and physically exhausting and leads to stress at home and at work. But speaking from four years of experience working two jobs, here are some tips for surviving a second job.

1. Do Something Different, or Even Fun

If you’re at a desk all day, avoid computers at night.

You might find that standing at a cash register or the bustle of waiting tables is a refreshing change from your cube. If you can relate your second job to an interest, all the better. Love animals? Try walking dogs. Like music? Usher at concerts.

2. Watch The Stress

Most jobs carry some degree of stress, but if your primary job has you popping antacid tablets like they were tic-tacs, don’t become an air traffic controller by night!

Keep tabs on your on-the-job stress levels at your second job. If you’re a motivated employee (as you probably will be since you’re already willing to work two jobs), you may be targeted for a supervisory role, for example.

Take on additional responsibility with caution. A promotion may mean a few more dollars, but it may not be worth it if your stress level goes through the roof.

3. Tread Carefully at Your Day-Job

To tell your boss, or not to tell?

I’ve always wrestled with this one. On one hand, I didn’t want my boss to think that working a second job would subtract from my ability to do my primary job well, but I always wanted my boss to understand why I was leaving promptly at 5 on certain nights.

Also, I always figured that working a second job was a subtle hint that a raise might be in order! But be cautious if you decide to take on a second job. Many employers won’t allow you to do any sort of extra work if it is remotely related to your day-job, while some employers won’t allow moonlighting at all. Those air traffic controllers, for example, are prohibited by the FAA from moonlighting, lest they be tired on duty and miss two jets converging head-on. If in doubt, ask. I’ve concluded honesty is the best policy here.

4. Find a Flexible Boss

Obviously your full-time job comes first.

So be honest with your second employer if you will need time off to perform well at your primary job. This might include time to take a trip for work or put in the hours needed to do well on a particular project.

While small, independently-owned businesses may be more understanding of your particular position, they may not have the staff levels to accommodate your requests. On the contrary, many large chains offer extremely flexible scheduling, especially if they are able to cover shifts with staff from other nearby locations.

I’ve worked second jobs at both Starbucks and two smaller, locally-owned businesses. While their were benefits to both, I can definitively say I had infinitely more scheduling flexibility with Starbucks.

5. Set Earnings Goals

Before taking a second job, figure out how much extra you want to make each month and only work the hours needed to reach your goal.

If you can, designate your extra income for something tangible, like paying off a credit-card or funding a savings account. Seeing the results of your work will make the grind easier.

6. Keep Your Down Time

Nobody should work 24/7.

Make sure you’re off at least one night and one full day each week. And if you feel like you are missing out on socializing because of extra work, remember that you are saving the dollars you would be spending on drinks or entertainment.

Moonlighting will put stress on you, but it may put even more stress on your relationships.

If you can, talk to your spouse or partner before taking a second job, and be cognizant of how he or she is feeling after you’ve been working the extra hours for a few weeks. Be careful, too, not to neglect social activities. Work too much, and you may find your friends stop calling because they assume you’re unavailable. Bottom line? It’s easier to find other ways to make extra money than it is to find new friends or a new relationship.

8. Beware the Tax Man

If you work limited hours, your second paycheck may not withhold enough in federal taxes each week, even if you select zero exemptions on your W-2.

Take the time to calculate your approximate tax liability with your additional income and specify an additional amount to be withheld each week. Even better, put that money in an interest-bearing account. You will owe Uncle Sam come tax season, but you can pocket the interest!

9. Watch Your Body

I’m not going to preach about healthy lifestyles here (alas, I have a long way to go myself).

I know from experience, however, that the additional fatigue from working two jobs will amplify the effects an unhealthy lifestyle takes on your body. When you work two jobs, you’ll be getting less sleep, though your body actually needs more. You’ll be eating faster and, most likely, less healthfully, when you actually need more nutrition.

Finally, you’ll be tempted to consume more caffeine to get you through the day, when it may keep you from getting the good rest you desperately need. If you can squeeze it in, exercise, a balanced diet, and at least six hours of sleep will make a big difference in your ability to handle a second job.

(I had a friend who would stay up all night and then work a full shift beginning at 5 am on nothing but coffee. Asked how he did it, he said “I took a multivitamin.” Let’s just say I wouldn’t recommend that!)

10. Know When to Stop

Unless you have to work two jobs just to meet the bare necessities, always have an exit strategy.

What has worked well for me is to work a second job for a year, take six months or so off, then start a new second job. I enjoy the challenges of learning something new and meeting new people, but am cautious not to go too long without some downtime.

The beautiful thing about working a second job is it makes you appreciate your free time so much more.

Have you had experience juggling more than one job? I’d love to hear about your experiences and how you survived your second job!