A person in their late 40s with $145,000 in debt and $300,000 in their 401(k) is considering refinancing their 3.5% mortgage. Financial experts advise carefully weighing the pros and cons, considering factors like current interest rates, closing costs, and the long-term impact on overall debt. Refinancing could potentially lower monthly payments, but it's crucial to analyze whether the savings outweigh the expenses and if it aligns with their financial goals, especially with a significant retirement nest egg already in place.