My Chevy Malibu's coolant is overheating after I fixed a vacuum tube

So I was trying to get to my throttle body on my 2001 Chevy Malibu to clean it and I accidentally snapped a hard plastic line coming from the back of the engine to the air duct. I went to my local O'Reilly's and the guy over there told me that it was a vacuum line. He said that if I connected the two pieces with a hose, put on a unicoil to prevent a kink and secure it with clamps, it should work like normal. I've done that and when I took it around the block for a test, the engine temp got abnormally high. The throttle response was sharper and the the revs were consistent with the amount of gas I put in, but the coolant temp got halfway up the gauge after 4 minutes on driving at 35mph. Is there anything that can be done to keep the temp down?

The attached picture is of the vacuum hose.