Heat cramps?

I worked out on the bike at the gym this morning. Normal room temp. Worked out pretty hard. Sweated a lot. Drank water during the workout.

After working out, for pretty much all day at work, I felt weak and had tremors, like one gets after using Albuterol (an asthma medication) or has a lot of caffeine. Also, my lower legs were cramping a little, like I needed to give them a good stretching. It was a good enough excuse not to lift weights at lunchtime.

Could this have been heat cramps? I thought I had hydrated enough. I made it a point to keep drinking fluids throughout the day, so I know I'm not dehydrated now. I don't think it was low blood sugar (I'm not diabetic, but have had a few episodes of hypoglycemia in the past). I've also thought it could be an electrolyte imbalance.

I guess I thought heat cramps or an electrolyte imbalance would be unmistakeable. Would do you think?