What does it include? All of your staff must understand what they need to do if there is a fire or if they are asked to evacuate the building. This goes beyond special fire warden training to training or information sharing for all staff.
Things like an emergency exit route, where the assembly point and where the calling point of the fire alarm is must be known and understood by everyone. There is also a duty on employers to pass on to staff the findings of their fire risk assessment.
This need to be done for all staff, but can also be built into fire warden training too. If you have enough staff that need training, it is probably more worth your while to bring a fire consultant in to your premises and do on site training specially tailored to your needs. You can also opt for effective fire warden training via https://firstaidtraininggroup.com/fire-warden-fire-extinguisher-combination-course/
This is also likely to work out more cost effective than sending people away to do a standard course. Fire warden training should cover the basics of fire safety and prevention, including the fire triangle (oxygen, heat and fuel), which explains that three things you need for a fire to start.
It must also include the basics of the main law relating to fire safety at work and understanding of how fires spread through the building. Most of the training for Fire Wardens will include practical sessions on how to use fire extinguishers.
This is very important in making sure people are confident about tackling a fire if that is part of their role in an emergency. The session could include using several extinguisher types and even fire blankets too. Specially tailored sessions can also include training in any special roles in an emergency, such as having to check certain areas, switching off any equipment or plant and helping less able people out of the building.