Climate change is intensifying occupational heat exposure, posing risks not only for heat-related illness but also for sleep, which is essential for recovery, safety, and productivity. Heat-exposed workers are highly vulnerable due to prolonged exposure, limited access to cooling, and poor housing. This systematic review aimed to synthesise global evidence on how occupational heat exposure affects sleep quality among workers across different occupations and settings. A systematic review was conducted following Synthesis without Meta-Analysis (SWiM) guidelines. PubMed, Scopus, and Google Scholar were searched (2000–2025) for studies involving adult workers (≥18 years) reporting both heat exposure and sleep outcomes. The review was registered with PROSPERO (ID: CRD420251125735). Of 7,108 records screened, 11 studies met the inclusion criteria. Studies spanned Asia, Australia, North America, and global cohorts. Heat exposure consistently impaired sleep quality and duration. Using Pittsburgh Sleep Quality Index, Actigraphy, and self-reports, common complaints included difficulty falling asleep (64%), restlessness (54%), non-restorative sleep (54%), night sweats (36%), and reduced total sleep time (45%). Night-time temperatures above 25°C and high workplace wet bulb globe temperature values were strongly linked with reduced sleep efficiency and delayed sleep onset. Vulnerable groups included shift workers, petrochemical and steel labourers, women, older adults, and low-income workers in urban heat islands and poorly ventilated housing. Occupational heat exposure disrupts sleep, compounding daytime strain and creating a dual burden for workers. Integrating sleep into heat stress management through cooling interventions, better housing, and revised work–rest schedules is critical for workers well-being in a warming climate.

INTRODUCTIONWhilst only 5.5% to 7% of breast cancer occurs in women less than 40 years of age in the West, the incidence has been reported in up to 18% in Asian population. This study seeks to evaluate our unit's experience in breast cancer in young women.

MATERIALS AND METHODSA retrospective review of our database identified women with newly diagnosed breast cancer from January 2006 to February 2011. Patient demographics, clinical presentation, imaging and pathological findings and treatment received were determined.

RESULTSOut of a total of 1160 women with breast cancer, 135 (11.6%) were under 40 years of age and made up our study population. The most common presentation was a self-detected breast lump. Most patients did not have a positive family history. Mammography demonstrated abnormal findings in 78% of patients. Ultrasound was very sensitive in the evaluation of a breast lump and demonstrated abnormal findings in 95%. Out of 129 women, 40 (31%) underwent breast-conserving surgery of which 5 (12.5%) proceeded to mastectomy due to involved margins. Also, 89 out of 129 women (69%) underwent mastectomy of which 19 (21.3%) had immediate reconstruction. Of a total of 121 primary resections, 94% were invasive ductal carcinoma while 15.5% were pure ductal in-situ carcinomas. The majority (61.2%) showed high grade disease.

CONCLUSIONMost young breast cancer patients present with a self-detected breast lump and do not have a positive family history. A strong clinical index of suspicion and appropriate breast imaging workup are useful for the early and accurate diagnosis of breast cancer in young women.

Adolescent ; Adult ; Age Factors ; Breast Neoplasms ; diagnosis ; epidemiology ; surgery ; Female ; Hospital Units ; Humans ; Retrospective Studies ; Singapore ; Young Adult