The boss is away but it's no time to play - not if you're the deputy. Better hold your nerve, warns DARIUS SAMAI
It's Monday morning, nine o'clock, and you have staggered into the office after a weekend drinking too much punch at a summer barbecue. Sitting on your desk is a file marked "Demanding immediate attention". You peer inside, scan its contents, and the implications are far too complex for you. You'll drop in on your boss and ask her to make a decision, tactfully couched as an opinion, as you normally do.

Then you peek over in the direction of your boss's office and your heart sinks. It's empty, the door is locked and the light switched off. You remember the date. She's on holiday. For three weeks. Some remote Greek island. There is no boss. You're the one in charge now.

Tens of thousands of office workers are confronted with this stark reality every summer - and often several times a year. Holidays are the main cause, but bosses go on maternity leave, get sick, and get hit by buses. Some of us revel in the sudden elevation to decision-maker - like Al Haig, President Reagan's national security adviser, who, when Reagan was shot and hospitalised in 1981, famously commented that "I'm in charge now". (He wasn't - vice president George Bush was, as Haig was impelled to acknowledge very soon afterwards.) For the less power-hungry, it can be a time fraught with unexpected difficulties.

David, 29, works in the human resources department of a City firm. His department manager went on a three-week holiday just three months after he joined, and the director the manager reported to was off sick for a week at the same time. "It was a total nightmare," he recalls. "I had to do my own work, plus the workload of my manager, and make financial and logistical decisions which I hadn't really been prepared for. Because the director was away for some of the time I had to go to meetings with the other directors where they were all, 'Well, what are you going to do about this?' I couldn't give them an answer.

"My manager's secretary was very snooty, like 'I'm not taking orders from YOU'. Everyone else was very nice about it, constantly saying it was unfair to expect me to cope with everything, and not to worry. But when it came to the crunch they expected decisions to be made." David prevaricated and fell behind, going home late and in an irritable state every night. "My boss had a very fat folder in front of her when she got back, and I was so relieved I just lay low and beavered away."

Paul Taffinder, a partner at Andersen Consulting and author of The New Leaders, a handbook on management change, says a boss's holiday is invariably stressful for deputies but can also be a time when underlings come into their own. "Quite a lot of future leaders develop successfully when their bosses step out of the frame for a period of time, and studies have shown higher stress levels can actually improve decision-making capabilities," he says. Able deputies may see a boss's holiday as a time to show themselves off, welcoming pressure and signalling to management that they can do the job just as well themselves.

Taffinder, a chartered psychologist, says the effect on the individual standing in for the boss also depends on the structure of the company. "The old, hierarchical, authoritarian structures like banks, insurers and government bureaucracies are worse. Difficulties will come when he or she is confronted with a big change which nobody knows how to cope with - the system isn't set up to deal with those."

Problems can arise on a more personal level as well. Some companies have very political workforce atmospheres, where petty divisions and niggling resentments can explode when the boss is away. Susannah, who works at a senior level in a property-related firm, originally relished the chance to take over when her boss took his first long holiday. "But my business world is very male dominated, and the office was having none of me being in charge," she says. "They'd ignore me or go over my head, and only stopped when the MD made it clear they should deal with me."

Relations were never the same with her colleagues afterwards, and she moved to another division. "My boss had made it clear I was to be in charge, and I was as polite and friendly as I could be while he was away, but some of the men didn't want to know," she says. "It was very petty, and made everyone look bad."

Even if a workforce realises that it's probably counterproductive to give an acting boss a hard time, holiday times can result in different problems for different people. Just as managers have varying managing styles, depending on their training, personalities and the latest fads, so stand-ins can find themselves clashing with their absent bosses' personalities.

A deputy who is quiet, introverted and careful with everyday detail may find himself standing in for a boss who is sociable, extroverted and more concerned with the broader picture. "In this case," says Claudia Herbert, head of the Oxford Stress and Trauma Centre, "the deputy might have problems reading what he or she thinks the boss's decisions would be in every scenario, and could start feeling very nervous and out of his depth, making panic decisions without being able to think them through." In the worst case timid deputies could find themselves in a vicious circle, becoming paralysed with worry that they are not meeting their bosses' expectations, without feeling they can think for themselves.

Herbert, a clinical psychologist, says that if the situation is reversed, and a more extroverted and sociable deputy stands in for a methodical, introverted boss, the results could be more positive. "He might, by nature, feel less pressure and more able to seek the help of others, while the introvert will try to solve everything himself. It will also help him to build relationships rapidly." The downside is that if the job requires constant decision-making, the extrovert stand-in is less likely to do it.

So is there any way out of temporary boss hell? Possible solutions, says Herbert, are to prepare more thoroughly for holidays, with the boss holding a meeting not just with the deputy, but people from all departments. Even hiring a temp might help, because a hapless stand-in is often left with two peoples' workloads, and the key to seeing through holiday periods is to make sure everyone communicates well with the deputy, reducing his or her stress levels. And it's not a good idea to go on holiday just before a large order or restructuring is due. "You'll exacerbate a stressful situation tenfold by going away," she says.

Even when everyone has the best of intentions, standing in can be a fraught business. Andrea, 38, took over as editor of a small magazine when the incumbent went on maternity leave for five months. "People were very willing to help me out, perhaps because I only had the job temporarily and they knew I hadn't fought my way into it," she says. "It was a great experience because everyone comes to you, asking you things, and you find yourself making decisions and feeling you're quite good at it.

"But when the editor came back, I suddenly felt quite superfluous. One day everyone was passing everything they were doing through me; the next I was back to being a deputy and felt pointless," she says, a little wistfully.

"Having had a taste of being boss I just couldn't go back to my old job." Andrea resigned a few months later.