"Don't get so worked up!"

• Refrigeration mechanic's "Stay cool!"?
• Laid up in house with minor wound for dressing, relax
• Relax (informal)
• Relax, to a refrigerator technician?
• Take it easy
• Kid almost a yob? Relax
• Prelude to a fever abroad? Don't worry
• "Dude, relax!"

Wiktionary Word definitions in Wiktionary
n. (context colloquial English) A period of quiet, rest and relaxation, especially after a party etc.