pulling this out of my head

hot or cold compress to the skin works on the gate control theory...the skin nerve fibres block the sensory (in the brain) interpretation of the perineal stretch

cold reduces blood flow to the area...reducing swelling but can also tense the tissue
hot promotes blood flow, but also acts to soften the tissue, allowing the stretch

You would have to have a hot compress on your peri for a good while to draw that much blood to the site and make it worse...but sitting on a (poorly designed) birthing stool can cause venous congestion and actually work to increase the risk of tearing

I had Jay in the bath...warm and yummy...and had a 2nd degree tear (had epis firts time round) but had no pain as water acts to cushion the peri

does that make sense?

xx yogababy