Leave that booth door open. Here's a very interesting report on interpreter workload commisioned by AIIC. It evaluates psychological, physiological, physical and performance aspects and the relationship between them. It turns out that stress eats us up on the long run but it doesn't seem to affect performance much. And that the booth is an asfixiation-inducing device, with unnaceptable CO2, humidity and temperature levels. As if we hadn't noticed that.