I hit my head on the freezer door when i stood up after putting something in the fridge. i put ice on immediately, just localized pain now. go to er?

ER visit: A visit to the er is not necessary unless you've lost consciousness, have a severe headache or are undergoing a character change. Ice should suffice to reduce the swelling.

Monitor yourself: Based on your description, the injury is not alarming and so er visit is not necessary at this time. If you develop significant headache, dizziness, nausea/vomiting, vision change etc...Then consult doc or go to er. Otherwise, mild localized bump and pain should get better in a few days. Good luck and happy new year.