If it's really cold out, and your match is outdoors, you have to run quick stages that cycle fast.
140 rnds and 5 stages when it's bitter cold? That's crazy.
How about 5 stages and 60-90 rounds?
Extremes of heat and cold present some dangers, and fatigue from extremes of temperature (being hot & dehydrated or being cold & frosted) can create safety issues, even with experienced gun handlers.
You can only learn from experience if you pay attention!