One of the most stressful moments when speaking at an event is actually not during your presentation, but the hours before your presentation. To some speakers, the wait can be so stressful that they completely lose their presence. As mother nature didn’t give humans an appropriate instinctive response to face the stress of a presentation, they adopt one of the basic survival techniques for protection: they fight the public, they flee, or they “play dead”. The longer they wait, the worse the problem becomes.
My advice is simple: put these speakers early in the program. You may want to put a seasoned speaker on stage first, but then I recommend that you don’t let the nervous ones wait for too long. This will greatly reduce the risk of meltdown on stage.
Of course, there are techniques to cope with stress. There are easy tricks, but when the source of the stress is a lack of self-confidence or self-esteem, that takes time to correct. In some cases, it can be a lifelong battle. If you feel some speakers are not going to manage the stress well, don’t make them wait for too long, it will make them feel miserable and they will not enjoy the experience.