you can use your voip service to have an after hours menu. Your first choice can be :
"if you believe that you are experiencing a medical emergency, dial 1". This sends it directly to your cell phone.
Not to nit pick, but I might say medical emergency call 911. If you have an urgent problem that cannot wait until the office opens tomorrow, dial 1.
In this litigious world you have to assume everyone is an idiot and give them permission to dial 911. Doesn't stop them from suing, but will give them less of a basis.
