Be Careful!

I have had this problem also, never caused harm to equipment however. Had a integrated amplifier that would go into protection mode. Even happened when using the remote (metal one).

As many have aforementioned, a discharge prior to touching equipment is best protection. ALso, as Elizabeth stated, bare feet, or even taking shoes off helps reduce static buildup. 

Like others have suggested I have a brass plate that is grounded to earth that I touch first.  My preamp crackles through the speakers if I don’t in this weather 

The latest Audioquest anti static vinyl cleaning brush uses the user as a ground, which I think is a bold use of the consumer as a participant in an audio issue remedy…this might be illegal in some states, but I use one anyway but store the little charge in a battery that I later use to power my toothbrush.

Humidifiers, anti static spray like Nordost and my Sonic Tonic or even Tourmaline guns or air ionizers, and Mapleshade used to sell the Ionoclast ionizer, long out of production.

I have one pair of very comfortable shoes (Skechers) that makes me get zapped from all metal objects (very unpleasant).  At home I walk barefoot, but at work I get zapped all the time.  I ended up saving these shoes for the rainy seasons.