The ornamental design for a body for a portableheater, as shown and described.
FIG. 1 is a right side front perspective view of a body for a portable heater showing my new design;
FIG. 2 is a left side rear perspective view thereof;
FIG. 3 is a front elevation view thereof;
FIG. 4 is a right side elevation view thereof;
FIG. 5 is a left side elevation view thereof;
FIG. 6 is a rear elevation view thereof; and,
FIG. 7 is an enlarged top plan view thereof.
The broken line showing of a front grill, a rear grill, top front control buttons, and a base are included for the purpose of illustrating environmental structure and form no part of the claimed design.