The phrase "to check the temperature" means to measure or gauge the current state or condition of something. It refers to evaluating the situation to understand what's happening at a particular moment in time. Full definition
Cook the turkey for 3 hours before checking the temperature of the meat. (howto-simplify.com)
Always check the temperature with your hand or elbow before emerging baby in the water. (health-foundations.com)
Setting it up will only take about 15 minutes, and once you're done, you'll never have to double or triple check the temperature before leaving your house again. (businessinsider.com)