For reference, split it between multiple print strings and terminate that sequence with a println.
To answer this question:
client.print("get /arduino.php?temp="); //print the constant string
client.print(temperature); //print the variable temperature's value, note the lack of quotation marks
client.print("&hr="); //print the constant string
client.println(heart); //finally send the variable heart's value and a newline, in order to submit the data
The OP's problem was that they were sending the request as a constant string, so what the server was getting was "get /arduino.php?temp=temperature&hr=heart"