how to use multiple transistor to switch single device so that each transistor has less load and desnt get hot?

i want drive a motor 12v havn't measured current but their product is enough to burn transistor can't i add more than one switch(transistor) so that current through each transistor is less or voltage or something like that that doesnt burn any thing. 

If you're using bi-polar transistors OR MosFets in a linear mode, then you can parallel them, but if you do, you need to put a series resistor in the emitter or source leads. If you are paralleling, and switching Mosfets in a digital, fully saturated mode, you don't need series resistors.
The best way is to use a transistor or mosfet rated for the power you need and a heat sink.

However if that is not practical connect them in parallel.

What transistor are you using and how much current is the motor drawing at start up? A motor draws the most power when it is first starting up. If the transistor is rated to handle that peak current then you need to add a heat sync so it doesn't burn out.

Like i said in your other thread, the heat is going to be there. Whether it's present in a single component or across many it will always be there it's just a matter of managing it. I suggest you look into a motor driver. It seams like your trying to make a motor driver from scratch here. There are IC's out there made for running motors.