When packing a lunch to take to the office or for your kid to take to school, try this hack to keep your food chilled: Freeze a container of yogurt! You’ll have a yogurt “ice pack” to help keep the rest of your food cold, and your yogurt will stay cold until lunchtime. It’s the right type of ingredient to freeze; a juice container or thermos of water may work the same way, but it’s slow to thaw out. Dairy items (like yogurt) freeze hard but thaw quickly. So by the time you’re ready to eat, it’ll be the perfect creamy consistency.