These pretzels are best fresh from the oven but if you need to store extra overnight, they heat up surprisingly well. Store them in an airtight container in the fridge, then heat them in the microwave to warm them. If desired, you can put them in the oven to try and crisp up the pretzel a bit before serving but I have found it takes way too long to warm the hot dog through this way and I always seem to overcook the pretzel.