Classic Pingi bags can not be recharged in the oven without damaging the product. If you do not have a microwave oven available, you can recharge the bag in the sun or on a central heating radiator if necessary. This, however, will take much longer than in the microwave oven and does not offer optimal results due to the irregular heating.
Exceptions are the Pingi ASB-1000 and DSB-600. These models were developed for oven recharging.