There are tables which deal this issue specifically. Though the total heat load remains constant at 300btu/child, sensible and latent heats vary as per the room temperature.
Temp. SH LH
82F 180Btu/person 220Btu/person
80F 195Btu/person 205Btu/person
78F 215Btu/person 185Btu/person
75F 240Btu/person 160Btu/person
70F 275FBtu/person 125Btu/person
For children you should consider 75% of these values, for the above quoted numbers are for adult males.
Regards,
Believe it or not : Had we trusted Archimedes and assigned him the work of lifting the earth(or any mass equivalent to that of earth on earth),with a lever of suitable length, it would have taken him 23 million million years to lift the earth by one centimeter, if he worked at the rate of 1 HP.