In case you're keeping score, yes your co-worker just took two-weeks off and you're left to do his/her work. So what are you going to do about it?
You can easily become the person who stays late every night carrying a double workload. You can just as easily become the person who does only what's reasonable for your boss or clients to expect when you're a man down.
Let's say you're the worker who wants to look like a team player and pick up the slack for your vacationing colleague. My advice is to proceed with caution. That's a dangerous road you're about to embark on. You want your clients to be understanding, your boss to think highly of you, your co-worker to cover for you when it's your turn to vacation. But, you don't want to be the go-to person who covers for everyone who takes a vacation. You certainly don't want to be the person who walks around the office resentful, snapping at anyone who dares to ask you a question because you're overwhelmed and overworked.
You may need to assess exactly what's expected. Is it just filling in for the person at a few meetings or handling all of their client calls. Is it short term, or could taking on someone else's responsibility for a few weeks lead to taking it on permanently. Yes, you definitely want to proceed with caution and have a conversation with your manager if necessary. Can that project wait for your co-worker to get back? Can you
Now, there can be a positive for you. Summer can be a great time to put some energy in the work side of work life balance. Covering for a co-worker on vacation can help you get ahead by proving yourself. Summer can also be ideal for pondering your desired future and trying out a role that interests you.
Most important, regardless of whether others take time off, don't be afraid to take your own vacation days. Even if you're the new guy or have lots on your plate, you need time off to re-energize and the slower summer tend to be the perfect for it. Even if you don't go anywhere, or can't afford to travel, taking time off helps keep you positive.
According to Project Time Off, employees who take most or all of their vacation time each year perform better, are more productive and more satisfied in their jobs.
If you are the vacationing co-worker, think about how you can make life easier on others while you're gone. You might leave specific instructions about what you consider top priority and what can wait for your return. Taking vacation knowing you've done everything possible to help out co-workers left behind benefits everyone. Hopefully, your coworkers will show the same courtesy to you.
It's normal to worry what covering for a vacationing co-worker will do to your workload. Ask for notes, figure out what's reasonable and have a conversation with your manager ahead of time. With lots of people gearing up to take summer vacation, you don't want to be the sucker in the office stuck there until midnight.