I agree. Really high heat primarily affects the maturation, not size. Iâ??ve had super-high temps before and the buds were just huge, and solid. Just the maturation was fucked up, (the quality after dry wasnâ??t very good).
So Iâ??d say the airyness youâ??re seeing is definitely not caused by heat. Probably not strong enough light, or else just the strain. Some strains Iâ??ve seen [like some Big Bud crosses] just make really fluffy, airy buds, even though theyâ??re really crystally.
btw vegging plants like the highest humidity possible until the point where it gets them wet. Same in flowering except it causes mold and mites so you have to keep it low. But it definitely wouldn't hurt thier growth.