I'm sorry to hear about the pain and swelling you're experiencing in your left testicle.

Pain and swelling in the testicle can have various causes, and while exposure to cold might cause some discomfort, it is less commonly the direct cause of testicular pain and swelling. Possible causes include:

• Infection or inflammation (such as epididymitis or orchitis)
• Testicular torsion (a medical emergency where the testicle twists, cutting off blood supply)
• Injury or trauma
• Hernia or other underlying conditions

Since you have swelling and pain that started suddenly, it is important to seek prompt evaluation by a urologist (a specialist in urinary and male reproductive health). They can perform a physical examination and may order an ultrasound to determine the cause and provide appropriate treatment.

In the meantime:

• Avoid heavy lifting or strenuous activity.
• Wear supportive underwear.
• Apply a cold pack gently to reduce swelling if it feels comfortable.
• Avoid self-medicating without professional advice.

If you experience severe pain, fever, nausea, or vomiting, please seek emergency care immediately by calling the emergency number provided.

Please consult a urologist as soon as possible for an accurate diagnosis and appropriate care.To narrow down potential causes, we will need some more information.Please tell me your age and gender. I understand you're having pain and some swelling in your left testicle since this morning.