I usually do the following:
1) Ask them to identify their top self-care activities and plan on doing those after the presentation
2) Discuss and name how we feel trauma in the body, and to stay attentive to it during the presentation for quicker intervention response
3) Provide permission to recognize the trauma and to go for a quick walk, or practice grounding during the presentation. Example: Thumb to pinky, thumb to ring finger, thumb to middle finger, thumb to pointer finger and reverse. Try to wiggle toes and do all of this at the same time with both and and feet
4) Seek confirmation that everyone is capable of self-care before starting.
5) Begin with something funny
6) Have a second person watching the group to intervene or provide a signal to change the momentum if needed.
7) Close with similar steps to bring them back into the present space.