Flu-like symptoms develop, e.g. diarrhea, nausea, fever, confusion, dizziness, weakness, and generally feeling bad.

出现类似流感的症状，例如腹泻、恶心、发烧、头晕，虚弱，同时自我感觉很不好。

youdao

And in general, flu symptoms including fever and chills, sore throat and body aches come on suddenly and are more severe than cold symptoms.

一般来说，流感症状包括突然出现的发烧、发冷、喉咙痛和身体疼痛，而且比普通感冒症状更严重。

youdao

Tiredness and fever are much more likely to be a sign of the flu coming on.

疲倦和发烧很有可能是流感开始的征兆。

《柯林斯英汉双解大词典》

Others may get flu-like symptoms such as fever, muscle and joint pain and headaches.

VOA: special.2010.07.12

Swine flu can cause fever, head and muscle pain,cough, sore throat and stomach problems.

VOA: special.2009.04.29

He came home wiped out and last night the fever and flu came back.

FORBES: Creating Alignment: 6 Lessons I Learned From My Sick Child

The other symptoms that accompany colds and flu, such as stuffy nose and a fever, are telltale signs that a viral infection is causing your cough.

CNN: Mystery cough? 8 possible culprits

But even with shorter regimens, both drugs will still have to be given with interferon alpha, the two-decade old antiviral drug made by Merck and Roche that causes nasty flu like side-effects, including fever and fatigue.

FORBES: Why Aren't There AIDS-Style Cocktails for Hepatitis C?