Body cold after workout?

After I train, my veins pop out and I feel pumped but after 3 hours or so, I have no vascularity whatsoever until hours later.
I thought it was my post workout meal but it's not.

This has happened to me since I can remember, I just wanted to know if it happens to you guys too.

edited:
just a thought:
could it be high cortisol levels?

It happens to when my bf starts gettin' really low, to the point where If I rest too long between sets my sweat will actually start feeling cold and I'll get the shivers.