We describe a single shot off-axis digital holography based on a Mach-Zehnder interferometic scheme for measuring temperature distribution of a microheater. The proposed scheme has the capability of reconstructing object phase image which is dependent of the temperature distribution in real time. Experimental results shows that there is a moderate linear relationship between the measured phase and temperature in the range of 20 o C to 60 o C. We expect that the proposed system can provide a very reliable and fast solution in various surface temperature distribution measurement applications.