Skim, no sugar or poison, please

I can tell how my iced coffee from Dunkin Donuts will taste based on the first sip. I order a medium iced hazelnut with skim. I used to add, No sugar, please, to the end of my order; however, I've found that not mentioning sugar at all is the best way to keep it out of my drink. Most of the times, it's cool and refreshing and the correct flavor. Other times, it's warm and watery or non-flavored. The best way to test how well the coffee has been made, is to stick the straw all the way down to the bottom of the cup and take a long sip. If sugar's been accidentally added, then you'll find out for sure. This morning, after having attended an early morning yoga class, I was particularly looking forward to my coffee. Normally, I don't take a sip until I arrive at my desk and have situated myself at my computer. When I took a sip this morning, it was like drinking battery acid. I swallowed a little bit, but managed to spit the rest back in the cup. There was a pool of something (hopefully meant for human consumption) on the bottom of my cup that created a sensation of 200 miniature knives poking me in the throat. I've since downed 2 glasses of water, and am hoping that my tonsils aren't melting and dripping slowly into my stomach. Tomorrow, maybe I'll get an iced tea...