Are you eating more carbs? Carbs heat my body up like a furnace. I swear considerable more in my workouts when bulking vs cutting and if I eat a big carb meal just sitting on the couch without a fan I'm sweating lol. I've never ran tren but I'd probably be a mess. This 1 test cyp in gunna run next bulk apparently makes you sweat a lot too so prolly gunna be a bad combo for me but I can't wait to try it.
I'm pretty sure it's the androgenicity of the gear that leads to excessive sweating, both through increased metabolism and CNS stimulation. That's why tren (3 times more androgenic than test) is so bad. That being said, having a big ass fat layer under your skin contributes, too.