I've tried just about everything. On a personal level, I've tried adjusting my routine, exercising at different times etc. Recently I got a bunch of blood tests done (thinking it might be issue with my thyroid) but everything came back clean, and we basically exhausted the idea that there's anything wrong with me.
I've also tried active/passive cooling, but the issue is that my body either adjusts and warms the material up, or it just doesn't seem to make a difference i.e. Air conditioning, so I'm guessing the solution is finding a way to lower my body temperature from the source i.e. internally.
It's not that I can't sleep, in the sense that I'm anxious or have too many thoughts running through my head. Once I do fall asleep, I sleep fine. It's that my body temperature is so elevated, that it interferes with my ability to fall sleep.
I would say that I'm a healthy guy. I exercise daily (around lunch time, so not late). I don't drink caffeine, smoke etc. I go to bed at 9pm everyday. I practice mindfulness etc. I feel like I have everything in my life under control, except my body temperature at night.
The only thing that's (kind of) helped was taking the supplement Glycine. Except it seems to be inconsistent, and I'm not exactly sure how it works. I don't think it necessarily lowers my body temperature, so much that it doesn't bother me as much? It's hard to explain.
Also, my body temperature is large in my shoulders/neck, although extends to my back. I assume this is related to the amount of muscle in this area.
There’s also this product if it’s just a matter of having the bed feel cooler: https://bedjet.com/
Also though, the way you describe it being in your shoulders/neck and extending to your back makes me wonder if it might be related to bad posture causing tension in that area? It’s just a thought I had - it may be way off topic, but it sounds like you’ve exhausted other explanations.
Iron based Reactive Oxygen Species (FeROS) generates the most amount of heat in the body.
Beta Alanine helps creates Super Oxide Dismutase (SOD) typically couple with a metal like Cu, Zn, Mn, Ni, Fe. Iron and Manganese share many pathways, and its thought MnSOD minimises the effect of FeROS.
Leucine in gram amounts can stimulate alot of protein synthesis which means you could just hang out in shorts and t-shirt during the middle of winter and not feel the cold.
You know your diet, so I would look there first, perhaps cut back on calories and workout first thing in the morning.
JMO