So you would say in the past tense "I lay on the bed because I was tired."

VOA: special.2010.02.11

I was tired so I went straight to my hotel.

VOA: special.2010.06.12

It is their first excursion so far from home, and she says her daughter is tired and hungry.

VOA: standard.2009.09.01

We are tired of this. This is why everybody in this room is so ticked off.

VOA: standard.2009.08.17