There are many ways to heat a bearing race, or small housing, to expand it as part of an installation process. Some folks use old deep fat fryers (Fry Babies or the larger Fry Daddy) to heat parts. Others have been known to use a torch, though that risks overheating some spots and under-heating others.
Lately we've had good luck with an electric frying pan. No need to put oil in it, so there's no risk of spilling or splattering hot oil during the process. Just lay the bearing or small component in the electric frying pan and turn the thermostat control to 150 or 200 degrees. You can go hotter if necessary to reach the required expansion, but why handle metal any hotter than necessary. You can often handle hot, dry bearings with welding gloves, making it easier to transfer and position the pieces, compared to using tongs or pliers to delicately maneuver items heated in hot oil.
If you're really careful and clean up really good, your wife might not even notice the outline of the bearing burned into the bottom of her electric skillet.