checking ambient temps?

when checking ambient temps do I take the thermometer on the cold side and average it with the hot side(not the surface temps but to two temp gauges I have set about 4" from the surface. I have a 20L.

Others may differ; here is how I look at it:

My hotside thermometer has the probe inside the warm hide, and measured air temp in the hide.
The "hot spot" is the floor surface temp under the warm hide, taken with a lazer temp gun.
I consider the cool side temp to be the ambient temp.

Ambient temp refers to the air temp of the cool side of the cage.

ok cool I thought ambient temp was the average temp for the whole enclosure. So, I just used the gun and inside the hot hide is 88 and the digital thermometer on the cool side which is about 4" off the cool side's substrate is 73-74 during the night and during the day cool side temp gauge reads around 78-79. Thank you!