There are many types of vacuum seal bags, but not all are heat resistant. Some materials used in vacuum seal bags, such as polyethylene and polypropylene, can withstand high temperatures without melting or deforming. However, other materials used in vacuum seal bags, such as nylon and polyester, will melt or deform at high temperatures. If you need a heat-resistant vacuum seal bag, be sure to check the product specifications to ensure that the bag you select is made from a heat-resistant material.