Thirst, dizziness, headache or dark urine can signal dehydration. Rest in shade, cool down and drink fluids if alert. Confusion, collapse or signs of heatstroke need urgent help.

Shivering, slurred speech or confusion after cold or wet exposure may be serious. Move to shelter, remove wet clothing and insulate the person while arranging urgent help.

Headache, nausea or dizziness after ascent can be altitude illness. Stop climbing; if symptoms worsen, descend and seek medical help. Confusion or breathlessness at rest is urgent.

Stop if injured and protect the affected limb. Severe pain, worsening swelling, deformity, numbness or inability to walk needs assessment; arrange help rather than pushing on.