Is it for Single Stage Paint or Base coat/Clear Coat?

It wont hurt anything by using it , it will take longer for flash off for your next coat .

If sprayed to heavy with it in cooler temps, you can get runs , sags, metallic mottling, tiger stripes, if you have good gun control it shouldnt be to big of a problem.
You might just turn in the material knob so it wont apply a heavy amount of color/Clear to help with some of these problems.

If in doubt buy the correct temp reducer , its not expensive I wouldnt think it would be more then 25 bucks for a gallon.
hell of alot cheaper then having to buy paint/catylist/reducer again if it doesnt come out right .

Spray