I may be looking at everything through a particular lens lately, but since I was just reading about this and you mentioned almonds, it may be a reaction to salicylate. Almonds are very high in salicylates. Chris Masterjohn writes this about the substance:
"Salicylates are aspirin-like chemicals that occur widely in the plant
kingdom. They have numerous biological effects, such as interfering
with vitamin K metabolism, inhibition of the COX enzyme that produces
prostaglandins from arachidonic acid, depressing the synthesis of
so-called 'glyconutrients,' and causing the mitochondrial membrane to
become leaky, thereby decreasing the production of the cell's major
energy molecule, ATP, while increasing the sensation of heat and
shutting off the burning of fat."
I am salicylate sensitive but sometimes cheat in the evening so that I can "sleep off" the deleterious reactions to some degree (unwise I'm sure) and find that a number of hours later - usually about 5 to 7 hours later - I feel like I'm burning up and throw off all the blankets. However, this could also be a histamine reaction, or both. I don't know if the sensitivity/decreased excretion itself is the problem or if salicylates can cause this perceived heat sensation alone; not much detail is provided by that quoted text, unfortunately, and I haven't read about this phenomenon elsewhere.