Today I went walking in the fields. Didnt really want to go, but did it anyway.

I walked for around an hour, had a cup of coffee from my flask and carried on.

After about 5 mins walking, suddenly my head felt funny. It felt like the feeling you get when you stang up too quickly, only worse. Like a huge rush in my head. It made me feel dizzy.
It has left me with a muzzy head.

It scared me because I thought I was going to faint...in the middle of the field full of cow muck!

Does anyone have any idea what caused this?

Jude x