Thermometer troubleS.... Help a noob?

ok so the thermometer is a digital aquarium thermometer with a probe it says the box is really hot and it does get hot after quite a few hours since i have yet to ventilate my closet which my box is in..... the problem is on top of being a bit hot I also think my thermometer probe is just getting heat from the lights.... the probe is black and im getting readings of up to 92 degrees when in fact i think it is more realistically 85 which i know is hot but still.... what kind of thermometer should i get and how should i place it in the grow box for good temp accuracy

thermometer will work, cut a small piece of aluminum foil
lay it loosely on the probe, kind of make a shroud for the probe, you'll get a much more accurate temp