Dry ice is solid carbon dioxide, which is extremely cold. You should wear gloves or other protective gear when you handle dry ice, but have you ever wondered what would happen to your hand if you touched it? Here's the answer.
When dry ice heats up, it sublimates into carbon dioxide gas, which is a normal component of air. The problem with touching dry ice is that it is extremely cold (-109.3 F or -78.5 C), so when you touch it, the heat from your hand (or other body part) is absorbed by the dry ice.
A really brief touch, like poking dry ice, just feels really cold. Holding dry ice in your hand, however, will give you severe frostbite, damaging your skin in much the same manner as a burn. Wear protective gloves.
You do not want to try to eat or swallow dry ice because the dry ice is so cold it can "burn" your mouth or esophagus.
If you handle dry ice and your skin gets a little red, treat the frostbite like you would treat a burn. If you touch dry ice and get frostbite so that your skin turns white and you lose sensation, then seek medical attention. Dry ice is cold enough to kill cells and causes serious injury, so treat it with respect and handle it with care.
So What Does Dry Ice Feel Like?
Just in case you don't want to touch dry ice but do want to know how it feels, here's a description of the experience. Touching dry ice is not like touching normal water ice. It is not wet. When you touch it, it feels somewhat like what you might expect really cold styrofoam would feel like… sort of crunchy and dry. You can feel the carbon dioxide sublimating into gas. The air around the dry ice is very cold.
The Smoke Ring Trick, But Don't Do It
The "trick" (which is inadvisable and potentially dangerous, so don't try it) involves putting a sliver of dry ice in your mouth to blow carbon dioxide smoke rings with the sublimated gas. The saliva in your mouth has a much higher heat capacity than the skin on your hand, so it isn't as easy to freeze. The dry ice does not stick to your tongue. It tastes acidic, sort of like seltzer water.