我正在发烧用英文怎么说

"I have a fever" 是在英语中表达 "发烧" 的常用说法。

来源：fever 是英语中表示发烧的常用单词。

例句：

I have a fever and a headache. (我发烧和头痛。)
The doctor said my fever was caused by the flu. (医生说我的发烧是由流感引起的。)
My fever broke overnight and I feel much better now. (我的发烧在一夜之间结束了，现在感觉好多了。)