捏把汗 (niē bǎ hàn) feel nervous; worry about sth. or sb.

Usage:

“捏把汗”指因为担心所以手上出了很多汗，好像手里捏了一把汗一样。形容心情非常紧张。关于这个词，人们经常使用的结构还有“为/替某人捏（一/两）把汗”“ 捏了把汗”等。
"捏把汗(niē bǎ hàn )" means one’s hands sweat because he/she is nervous about something or somebody. The common structure is "为/替（wèi/tì） somebody 捏（一/两）把汗(niē(yì/liǎng) bǎ hàn ) /捏了把汗(niē le bǎ hàn ) ".

Sentences:

1、Zuòwán shǒushù xǐnglái zhīqián, yīhù rényuán dōu tì tā niē bǎ hàn.
做完手术醒来之前，医护人员都替他捏把汗。
The doctors and nurses are all worried about him before he came to himself after the operation.

2、Háizimen de zájì biǎoyǎn nándù hěn gāo,, suǒyǒu de guānzhòng dōu wèi tāmen niē le yì bǎ hàn.
孩子们的杂技表演难度很高，所有的观众都为他们捏了一把汗。
Those children’s acrobatic performance was so difficult that the audience all worried about them.

原文链接