The training for aid workers really depends on where the aid worker is headed, the security and threat situation in-country, the size and resources of the NGO and what they can afford to have their workers trained in and so on.

For example, my SO went to Sudan last year, the group underwent training in a number of areas. Meaning everything from personal/group safety, first aid, map reading and navigation for E&E purposes, what to do/don't if taken hostage and more. Again, depending on the resources of the NGO, some of this training is lead by former military. With the current situation now developing in South Sudan, it really demonstrates the peril that aid workers could find themselves in a short time.

On the flip side. When she went to the Philippines in the aftermath of the recent typhoon, the training was more relegated to briefings as the security situation there was much more calmer and under control. Also with the large number of local and foreign military on the ground and in the skies, providing supplies and logistics etc, any requests for assistance on security issues, appropriate resources were close at hand.

I posted this link last year to a comprehensive aid worker security manual

Another good source of information is Operational Security Management in Violent Environments.