Symptoms Cold Flu Seasonal Allergy Fever Rare Usual, high (100-102 °F), sometimes higher, especially in young children); lasts 3-4 days Never Headache Uncommon Common Uncommon General Aches, Pains Slight Usual; often severe Never Fatigue, Weakness Sometimes Usual, can last up to 3 weeks Sometimes Extreme Exhaustion Never Usual, at the beginning of the illness Never…… MORE