Activating this trainer:

Press F1 at main menu.

Listen for 'Trainer Activated'.

Press desired hotkey. All hotkeys can be changed on the trainer.

Trainer Options:

NumPad1: Infinite Health

NumPad2: Unlimited Ammo

NumPad3: No Reload

NumPad4: Free Shopping

Notes:

Infinite Health: While active you receive no damage. If you deactivate this within a mission you have to restart the mission before you can take damage again.

Free Shopping: While active your money will not decrease when you purchase stuff.