2nd degree burn and physical work? (lifting etc.)?

I have a 2nd degree burn on the top of my wrist/forearm.The doctor has me covering it with silver sulfadiazine and wrapping it up for the next week,until my next visit.Am I going to be ok lifting boxes at work? The pain is usually minimal unless I let my arm hang straight down for a short while.I can't afford not to work because I have bills to pay but I don't want to do serious damage to my wrist/arm.They gave me a note saying I could go back to work with no restrictions when I asked for one but I'm still worried that lifting stuff and using it like I normally would might be bad for it.Any suggestions?