No antifreeze in reservoir

[OutofOrder]

Reservoir tank was drained during a repair, then supposedly filled back up by the garage (it was on my bill). My car is running just a tad hotter, but the gauge isn't even halfway to redline as before, but there is no visible liquid in the reservoir. Should I add more antifreeze to the reservoir? Or will I be ok until summer. I was planning on a system once the weather gets warm.

 

[spg]

I would fill the tank back to the proper fill point. It may have been filled at the service but as the air is bled out of the radiator and cooling system the coolant level in the tank goes down.