The question lacks some details in order to be answered. Nevertheless, let's just give some examples.
Given that you are to burn 10 kg of methane (CH4) from 0 to 20°C. The specific heat capacity of methane is 4.475 kJ/kg-K.
H = mCpT
H = (10kg)( 4.475 kJ/kg-K)(20-0)
H = 895.00 kJ
Because of the positive value of enthalpy, methane takes in heat.