Help Freezing Threads

No doubt I'm about to make myself look like an idiot but I can't figure out how to debug a multi-threaded server app. How do I resume execution of the app with the active thread (the one that hit a breakpoint) frozen? I've tried the "freeze" command on the thread context-menu. That only appears to work if I pause the running app, freeze the thread, then resume the app.

Any and all help or ridicule is appreciated.
Dan