The term cool one's heels is identified in base64 scheme by the sequence Y29vbCBvbmUncyBoZWVscw==, while the MD5 signature is equal to 0b16d3d46fba81cea334b913a226e44c. The ASCII encoding of cool one's heels in hexadecimal notation is 636f6f6c206f6e652773206865656c73.