Just remember that warm air rises and cold air sinks. Barring local wind conditions, this will be the case.
But there's another wrinkle.......
If you are hunting a stand that's on a hillside, and your stand is a "morning" stand, and thus on the uphill side of where you expect game to approach from, when you go to it in the pre-dawn dark your scent will SINK down the hill and/or pool on the ground, especially on a damp or high humidity morning with little or no wind. That means that you may potentially alert deer that will be under or downhill from you, UNTIL THE SUN BEGINS TO WARM THE AIR, and then it will rise.
We have a situation like this on one of the farms I hunt. It's a pretty steep hillside that runs N/S. If there's no wind to move the air, you will definately have a situation where the thermals will work BOTH ways on you in the matter of a few hours.
What I've done for this, is wait in the dark at the top of the ridge until the sun begins to warm the air, and then stillhunt down to my stand with the thermal air currents in my face.
A good technique to employ for thermal "scouting" on your hunting ground, is to get some colored smoke bombs, and light them off different times of the morning or afternoon to actually SEE what they are doing. It's quite educational and sometimes surprising. When it comes to winds and air currents, all is not what it seems many times.
I even learned some things one day while scouting on a windy day. I was on a west slope of a N/S running ridge, and there was a pretty good east wind that was blowing hard at the top of the ridge. I was on the protected side of the ridge, and out of the direct wind. I lit a smoke bomb and watched the colored smoke rise up (the thermal) in the still air until it hit the easterly breeze. It then moved pretty quick until it hit an eddy that was quite a ways downhill from me, where it then swirled down and the BACK up the hill at me! Had I been hunting in that spot for deer that were downhill from me, they'd maybe have gotten my scent stream direct, and I'd of never even known it.
The smoke bombs will also educate you as to any "sinks" (natural... albeit slight...low areas where your scent "pools"), even though there's a prevailing breeze or thermal.
Offer No Apologies.....
NRA Endowment Life Member