I will not be going over chainsaw safety, except to say that permission to use a chainsaw must always be obtained from proper persons at DCNR or Forestry, and that you should never saw alone. Agencies that oversee trail systems will often require volunteers to show proficiency and safety skills by taking a certification class. PPFF has a comprehensive chainsaw policy that includes a training course that the volunteer must pass and be regularly updated on. I will share a link to PPFF chainsaw policy in the resources.
Other hazards you may encounter include exposure to poison ivy, poison oak, poison sumac, venomous snakes, stinging insects, dehydration, hypothermia, or heat exhaustion. Remember, you are a volunteer, and no job you do is so important that you should risk your health or safety. Take a break when you need one and call it a day if conditions deteriorate.