[MadMax]

Try not to touch any metal connections unnecessarily. There are some ad hoc measures you can take to reduce ESD problems. Touching the metal body isn't an issue as it's a big heavy hunk of metal which would shunt all of the current flow through the body. The real risk is to apply an ESD voltage to an isolated point in the circuit so current blasts through a weak path to ground.

You could implement a poor mans ESD wrist strap by connecting a wire to a metal watch strap or even the buckle as long as it's in contact with your wrist. Connect the other end to something grounded like your computer case.

Grounding your PTW's metal body will put your body's voltage potential at the same ground plane (same voltage) as your PTW electronics. This is a safe condition to start working on your electronics.

Momentarily touching a grounded object will bring your body potential to ground, but further movement can accumulate static charge which is why a wrist strap is a better solution to continuously dissapate static charges.

Dissapating ESD can be done without much special equipment if you can adhere to a rigid procedure:

1. ground yourself (wrist strap)
2. ground the body of whatever you're working on

Not wearing particularly bad combinations of clothing can reduce rapid static buildup (e.g. fleece sweater and a cotton shirt). Dry winter air is not very conductive. Because of this ESD can build to higher voltages before either breaking down the air (spark) or gradually dissapating through slower ion transfer.