"difficult physical conditions" is correct and usable in written English.
You can use this phrase to describe a situation where a person must deal with not particularly good physical conditions. For example, "Hiking in the mountains can be difficult due to the difficult physical conditions, such as the high altitude and thin air."
Difficult physical conditions hindered the construction of railways in Transcaucasia.
In the heat and under more difficult physical conditions, that amount increases, he said.
During the 1960s, he did exemplary work at Ledlanet Nights, the music and opera festival in Scotland, conducting operas by Handel and Mozart, and his ingenuity in getting good results with limited resources under difficult physical conditions was highly praised.
The issue is the extraordinarily difficult physical conditions.
In fact, we consider these reactions to be normal, considering the very difficult physical conditions of undergoing chemotherapy with the added burden of developing neutropenia and the fact that we did not observe psychiatric disorders among these patients.
Research shows a nexus between disability and poverty: lack of access to adequate health care, housing and living conditions; difficult physical work; distress related to the struggles associated with poverty; poor educational resources; lack of employment opportunity and persistent stigma.
In addition to a large number of people in high density, physical conditions are difficult and thus it presents an opportunity for a large-scale disease such as influenza to take hold.
Wireless sensor networks (WSNs) are very useful to monitor physical conditions in large or difficult access environments.
"He will be difficult opponent to adjust to, because of his style of fighting and physical conditions.
However, the physical conditions of the cut-over peatswamp may be such that drainage required for agriculture will be difficult and costly to provide.
The physical conditions, however, are harsh.
