Will heat delay flowering in autos?

They will be just fine, there is no need to stress, the warm conditions won't make any noticeable difference. Indicas come from places like Afghanistan, Pakistan, Morocco and the arid regions of India, places that are usually very warm/hot during the flowering time. I have grown plants that receive outdoor temps of between 80 and 110 degrees and in full sun, all day every day and as long as they are watered correctly, never seem to suffer. Heat can increase trichome production. When it comes to harvest time, try to do so about 1-1 and a half hours after the lights come on and before the heat builds up, this will ensue your flowers will still have trichomes in peak condition and unaffected (by heat) healthy terpenes. No need to do anything weird like extended darkness or stupid things like ice treatment, just leave your plants to think they are safe and growing normally before surprising them with harvest. The last thing you want to do after weeks/months of careful cultivation is introduce some sort of artificial stress, parading as an urban myth/ghetto science and made up by people too high to think properly and without any real knowledge about how plants function, right before harvest. Harvesting healthy unstressed plants will ensure that you harvest the best quality flowers. Hope this helps,............ Organoman.