If you must eat a heated In & Out hamburger then I suggest the follow:<br />
First, scrape the ketchup, mayo and any other sauce that is on the hamburger and put it a side. Also take the vegetables out.<br />
Second, pre-heat a steak pan; put the hamburger separate form the bun on the hot pan<br />
Third, heat up both parts of the bun near the hamburger on the same hot pan (you can get some souce from the hamburger on it)<br />
Fourth, you can either put back the original ketchup, mayo and the vegetables or, better yet, get new ones from what you have at home .<br />
Bon Appetite