Stressful situations will often arise in the workplace, and it is up to you how you handle them. Assure the interviewer that you can control stressful situations.
"I am well trained when it comes to effectively managing stressful situations. Before losing my cool, I am sure to review the situation, break the issue down to the simplest factor, and work my way through the problem from there. When you look at most problems for what they are you can see that the majority of situations are simple to solve."
Entry Level answer example
"Stress is part of any demanding job, and I embrace it to the fullest. I take good care of myself and prioritize my workload to maintain a healthy balance in my stress levels."
Experienced answer example
"I handle stress very well, and when you call my references, they will attest to this fact. When I am under pressure on the job, I focus on the task at hand and make sure not to get distracted. Staying on deadline is very helpful, and I will delegate when necessary to alleviate some stress."